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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>COTECMAR-UTB at TalentCLEF 2025: Linking Job Titles and ESCO Skills with Sentence Transformer Embeddings</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Jhonattan Llamas</string-name>
          <email>llamasj@utb.edu.co</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Edwin Puertas</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Jairo Serrano</string-name>
          <email>jserrano@utb.edu.co</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Juan Martinez</string-name>
          <email>jcmartinezs@utb.edu.co</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Corporación de Ciencia y Tecnología para el Desarrollo de la Industria Naval</institution>
          ,
          <addr-line>Marítima y Fluvial (COTECMAR), Bolívar, Cartagena D.T. y C.</addr-line>
          ,
          <country country="CO">Colombia</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Universidad Tecnológica de Bolívar, Faculty of Engineering</institution>
          ,
          <addr-line>Cartagena de Indias 130001</addr-line>
          ,
          <country country="CO">Colombia</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2025</year>
      </pub-date>
      <abstract>
        <p>This paper describes the COTECMAR-UTB submission to Talent-CLEF 2025TaskB, which focuses on retrieving the skills most relevant to a given job title. Our approach is a lightweight, unsupervised pipeline that normalizes job titles and skill aliases, encodes both with the Sentence-Transformer paraphrase-multilingual-mpnet-base-v2 into a shared 768-dimensional space, and ranks candidate skills by cosine similarity. The model is used strictly in a zero shot with no fine tuning so the system is easy to reproduce and deploy. On the oficial Codabench leaderboard our run ranked 19th of 26 participants, outperforming the organizer's baseline by two positions. Although the gap with top systems remains considerable, the result confirms that a multilingual of the shelf encoder, combined with simple text enrichment through synonym lists, can deliver competitive performance without task specific training. We analyze strengths and failure cases of our system and compare it against recent state of the art methods that leverage supervised fine -tuning, contrastive learning, or graph-based modeling. Our findings highlight practical direction, such as skill frequency reweighting and knowledge graph integration for boosting retrieval accuracy while preserving the portability of zero shot embeddings.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Sentence transformers</kwd>
        <kwd>Multi-label classification</kwd>
        <kwd>Natural language processing</kwd>
        <kwd>ESCO dataset</kwd>
        <kwd>Human resources</kwd>
        <kwd>Job recommendation</kwd>
        <kwd>Job matching</kwd>
        <kwd>Job skills</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        The management of Human Resources (HR) is essential to every organization. A human resource is
any person who is compensated for providing skills or knowledge that help an organization achieve its
business goals [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. The HR department assumes this responsibility by overseeing workforce development
and performance, strengthening employees’ skills and capabilities, and ensuring compliance with
International Labour Organization (ILO) standards [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. In doing so, HR enhances the organization’s
competitiveness and overall efectiveness and manages the entire recruitment cycle, from posting
job ofers to interviewing and selecting the most qualified candidates [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. The process of posting job
openings and selecting candidates is critical for hiring the right person for the role the organization
needs. Successful hiring, however, depends on a clear understanding of the current labour market, a
precise definition of each position, and an explicit identification of the skills the role demands.
      </p>
      <p>
        To streamline this matching process across languages and data sources, a standardized taxonomy of
occupations and skills is indispensable. The European Skills, Competences, Qualifications and
Occupations (ESCO) taxonomy ofers a multilingual, hierarchical classification of thousands of occupations
and skills, maintained by the European Commission [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. By normalizing both job titles and skill labels
to ESCO, HR systems can guarantee consistency and interoperability.
      </p>
      <p>
        At the same time, socio-technological landscapes are evolving at an unprecedented pace, industries
and workplaces are rapidly changing. Technological advances, such as task automation and Artificial
Intelligence (AI), are reshaping the labor market by creating new roles that demand specialized skills,
often dificult to source [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. Recent progress in Natural Language Processing (NLP), particularly the
Transformer architecture [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ], has shown that language models can achieve reliable accuracy in mapping
job titles to skills. Building on this insight, we adopt the multilingual sentence-transformer
paraphrasemultilingual-mpnet-base-v2, which produces high-quality embeddings while remaining computationally
eficient. By combining these embeddings with synonym enrichment from ESCO in an
embeddingbased retrieval pipeline, our system delivers accurate skill predictions for a given job title with minimal
computational overhead.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Related works</title>
      <p>
        NLP has become integral to contemporary HR analytics, powering applications that range from
automated parsing of curriculum vitae to candidate–job matching. Résumé analyzers, for instance, extract
structured information—education, experience, and skills—from otherwise unstructured CVs,
allowing recruiters to screen applicants eficiently. Furthermore, semantic matching techniques compare
candidate profiles with job descriptions, improving recommendation accuracy and fit scoring [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ].
      </p>
      <sec id="sec-2-1">
        <title>2.1. Pre-trained Transformers in Job Title Embeddings</title>
        <p>
          The rise of transformer-based language models has significantly influenced job-title embedding and
job–skill matching. The Transformer architecture enabled context-aware representations that
outperform earlier static embeddings, laying the groundwork for modern approaches [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ]. Building on
BERT-style encoders, early HR-domain work began to model job titles with pre-trained transformers.
For example, JobBERT performed a generic BERT model with information about co-occurring skills to
better capture job title semantics [
          <xref ref-type="bibr" rid="ref8">8</xref>
          ]. By incorporating skill labels extracted from job postings, JobBERT
achieved considerable improvements in job title normalization tasks over using a generic sentence
encoder. This demonstrated that skills can enhance transformer-based title embeddings, opening the
door for more specialized models in recruitment AI.
Subsequent methods leveraged skill data more directly to learn job title representations without extensive
manual labeling. Zbib et al. (2022) proposed an unsupervised learning approach using “noisy” skill
labels for training a job title similarity model [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ]. Instead of curated title pairs, they used skill
cooccurrence in job postings as a weak signal for title similarity. This approach proved as efective as
supervised techniques while avoiding costly labeled data, yielding strong results on job title ranking and
normalization tasks. In parallel, Anand et al. (2022) tackled the job–skill matching from the opposite
angle: given a job title, predict its required skills [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ]. Their model used a pre-trained Language-agnostic
BERT Sentence Encoder (LaBSE) to rank skills by importance, under the finding that important skills
appear frequently across similar job titles. By training on large-scale title–skill associations with weak
supervision, the model learned to predict skill importance for a job title and even generalized well
to other languages [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ]. These works confirmed that skill information – whether used to learn title
embeddings or to infer relevant skills – can substantially improve matching performance.
        </p>
        <p>
          Further extending skill-based representation learning, VacancySBERT was introduced, a Siamese
network to jointly embed job titles and skills [
          <xref ref-type="bibr" rid="ref11">11</xref>
          ]. They trained a RoBERTa-based model on an enormous
dataset of title–description pairs with a novel objective linking titles to the skills mentioned in their
job descriptions. The resulting encoder outperformed both generic encoders (e.g. BERT,
SentenceBERT) and prior job-specific models. Notably, VacancySBERT achieved a 10% improvement (and up to
21.5% when skill features are included) in recall@K over baseline methods. This marked a significant
leap in distantly-supervised job title embeddings, showing that massive-scale training on title–skill
co-occurrences can yield very robust representations.
As the field matured, focus expanded to multilingual and more sophisticated training regimes. Anand
et al.’s use of LaBSE hinted at multilingual capability [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ], but a dedicated solution arrived with Deniz
et al. (2024)’s multilingual job title encoder [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ]. They introduced a two-stage learning strategy: first an
unsupervised pre-training on skill and title co-occurrence across 11 languages, followed by a supervised
contrastive fine-tuning using known similar/dissimilar title pairs from the ESCO skill/job taxonomy [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ].
This combined strategy yielded a state-of-the-art multilingual job title representation model. In fact, the
new model achieved a 4.3% improvement in mean Average Precision (MAP) on English rankings over the
previous best monolingual model, and it maintained strong performance in all 11 tested languages [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ].
The learned embedding space also exhibited excellent cross-lingual alignment, enabling job matching
across languages. This was a crucial step as it globally aligned job title semantics, allowing, for example,
a French job title to be matched to its English equivalent via vector similarity.
        </p>
        <p>
          Meanwhile, other work explored alternative sources of supervision beyond skill tags. Laosaengpha et
al. (2024) proposed learning job title representations directly from their full job descriptions instead of
only the extracted skills [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]. They designed a Job Description Aggregation Network that encodes the
rich free-text content of job descriptions and uses a bidirectional contrastive loss to align each title with
its description in embedding space. This approach captures additional context (e.g., responsibilities and
qualifications) beyond just skill keywords. It outperformed a purely skill-based title encoder on both
in-domain and cross-domain evaluations, demonstrating that aggregating detailed job description text
can yield more informative title embeddings [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]. Together, these advances in contrastive training and
multilingual modeling have pushed job matching systems to be more accurate and applicable across
global job markets.
The most recent generation of solutions integrates structured knowledge and extends beyond job titles
alone. Fabregat et al. (2024) introduced an inductive graph neural network (GNN) that combines textual
embeddings with a job–skill knowledge graph [
          <xref ref-type="bibr" rid="ref14">14</xref>
          ]. In their framework, job titles and skills are nodes
in a graph (e.g., derived from a taxonomy like ESCO), and a GNN propagates information between
related jobs and skills. This inductive GNN approach enables the model to learn from both unstructured
text (job title descriptions) and structured relationships (skill taxonomy). As a result, it can make more
accurate job and skill recommendations, even handling previously unseen skills or titles by leveraging
the graph context [
          <xref ref-type="bibr" rid="ref14">14</xref>
          ]. This graph-enhanced method highlights the value of domain ontologies in
improving AI-driven matching.
        </p>
        <p>
          In a similar vein, Alonso et al. (2025) explicitly leveraged an expert curated knowledge base – the
U.S. O*NET database – to improve job matching and skill recommendation [
          <xref ref-type="bibr" rid="ref15">15</xref>
          ]. O*NET provides a
structured mapping of occupations to required skills. The proposed approach uses transformer-based
text representations of job postings in conjunction with the O*NET occupational data to recommend
relevant skills and match candidates. By anchoring textual analysis to a knowledge base, the system
benefits from authoritative job-skill relationships. Alonso et al. report that this knowledge-infused
transformer model yields better alignment between job descriptions and required skills, and aids in
matching job titles to suitable candidates [
          <xref ref-type="bibr" rid="ref15">15</xref>
          ]. This represents a trend of combining AI with
humancurated knowledge for superior results.
        </p>
        <p>
          Finally, researchers have begun to bridge job matching across document types, not just title-to-title
comparisons. Rosenberger et al. (2025) presented CareerBERT, a model that maps both resumes and
job titles into a unified embedding space for recommendation tasks [
          <xref ref-type="bibr" rid="ref16">16</xref>
          ]. CareerBERT is built on
transformer encoders fine-tuned to align a candidate’s resume with relevant ESCO job titles, enabling
personalized job recommendations. Through a two step evaluation (automated and human expert
review), CareerBERT was shown to outperform prior embedding-based approaches to job matching,
while providing robust, meaningful recommendations in practical settings. In particular, it significantly
outscored traditional methods when matching resumes to open positions, and human recruiters found
its suggestions more relevant on average [
          <xref ref-type="bibr" rid="ref16">16</xref>
          ]. This exemplifies the cutting edge of the field: using
transformer models to integrate rich textual data (like resumes) with standardized job representations,
thereby extending the scope from job–job similarity to candidate–job matching.
        </p>
        <p>In summary, the field of job title embedding and job skill matching has evolved from early text
similarity methods to sophisticated AI models leveraging transformers. Progress over the past few years
is marked by incorporating domain specific information (skills, descriptions), adopting unsupervised
and contrastive learning to overcome data scarcity, expanding to multilingual contexts, and integrating
knowledge graphs and databases for context. The latest approaches even cross traditional boundaries to
align diferent data modalities (resumes vs. job postings). This chronological progression underscores a
clear trend: increasingly specialized and hybrid AI techniques are pushing the state of the art in linking
job titles with the skills and candidates that define them.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Methodology</title>
      <p>Our system is an embedding-based pipeline (Figure 1) that retrieves the most relevant skills for a
given job title by encoding both titles and skills into a shared 768-dimensional semantic space. We
employ the pretrained Sentence-Transformer paraphrase-multilingual-mpnet-base-v2 as our
backbone because, in our internal validation, it yielded the highest Mean Average Precision (MAP)
among all models we tested, while public benchmarks also report strong average performance across
sentence-embedding and semantic-search tasks. The model is used strictly in a zero-shot without
additional fine tuning performed on the TalentCLEF corpus, so its role is purely inferential. Table 1
summarizes benchmark scores, inference speeds, and model sizes of leading pre-trained transformers;
paraphrase-multilingual-mpnet-base-v2 combines competitive speed with the best empirical
MAP in our experiments. The subsections that follow describe each stage of the pipeline in detail, from
input normalization to the cosine-similarity ranking that produces the final ordered list of predicted
skills.</p>
      <sec id="sec-3-1">
        <title>3.1. Input Data</title>
        <p>Avg. Perf.
The pipeline begins by ingesting the provided Task B dataset files. We used the JSON mappings of job and
skill identifiers to their textual variants: jobid2terms.json and skillid2terms.json. The jobid2terms.json
ifle provides a set of lexical variants (synonyms and alternative phrasings) for each job title identifier.
For example, the ESCO occupation ID corresponds to variants like “application developer”, “application
programmer”, “software developer”, “software engineer”, etc. Similarly, the skillid2terms.json file lists
textual aliases for each skill identifier (ESCO skill concept).</p>
        <p>For instance, a given skill ID might include variants such as “web services” and “web services systems”
as synonymous terms for that skill. In addition to these vocabulary resources, the input also includes
the list of query job titles (from the validation or test set queries file) for which the system must predict
relevant skills, and the full set of candidate skills. This stage outputs the raw textual data: lists of job
title terms and skill terms, indexed by their identifiers.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Cleaning and Deduplicate</title>
        <p>Before encoding the texts, we perform normalization and deduplication on the collected terms. All
job title and skill terms are lowercased and stripped of extraneous punctuation and spacing to ensure
consistency. We also remove any duplicate entries or trivial variants within the lists of terms. For
example, if a skill’s alias list contained both a singular and plural form of the same phrase, or exact
duplicated phrases, these would be consolidated to a single representative term.</p>
        <p>This cleaning step yields a refined set of unique job title phrases and skill phrases. The cleaned data
maintains mapping to the original IDs, ensuring that each job and skill identifier is associated with a
clear set of distinct textual representations. The output of this stage is a cleaned dictionary of job title
variants and a cleaned dictionary of skill variants, ready for embedding.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Build Skill Vocabulary</title>
        <p>In this stage, we construct the skill vocabulary that will be used for retrieval. Using the cleaned
skillid2terms data, we aggregate all unique skill alias phrases and organize them by skill ID. Each skill
in the vocabulary is thus represented by a set of one or more aliases – e.g., a skill ID might be associated
with the terms “pricing strategies”, “pricing tactics”, “pricing plans”, etc., as given in the dataset.</p>
        <p>The output of this stage is a complete list of skill entries (each with an ID and list of alias terms) that
will be fed into the embedding model. This forms the “corpus” of documents (skills) to be retrieved. We
note that a similar vocabulary is inherently defined for job titles via jobid2terms, but since in our task
the queries are single job titles provided in the test set, the job vocabulary primarily serves to supply
possible synonyms for better query representation.</p>
      </sec>
      <sec id="sec-3-4">
        <title>3.4. Load Model</title>
        <p>We then load the Sentence-Transformer model paraphrase-multilingual-mpnet-base-v2 into memory.
This model maps sentences or phrases to a 768-dimensional dense vector space (embedding). It has been
pre-trained on large-scale paraphrase data and indicates great performance across various languages,
helping us to create semantic relations between words, as shown in Table 1. We do not perform any
further training or fine-tuning on this model; it is used directly to encode texts in an of-the-shelf
manner. Loading the model yields a ready-to-use encoder capable of transforming any input phrase
(job title or skill phrase) into its vector representation. This stage’s output is the loaded model instance,
which will be used in the subsequent embedding stages.</p>
      </sec>
      <sec id="sec-3-5">
        <title>3.5. Embed Queries (Job Titles)</title>
        <p>In the query embedding stage, each input job title query is converted into an embedding. For a given
job title query, we first identify its canonical ID or find its synonyms in the jobid2terms mapping (if
available). If the query exactly matches or is contained in the list of variants for a job ID, we leverage
all those lexical variants to enrich the query representation. Specifically, we encode each variant phrase
of the job title using the Sentence-Transformer model to obtain an embedding. We then compute
the average of these embeddings to produce a single vector representation for the job title query. For
example, if the query is “software developer” (which has synonyms like “software engineer”, “application
programmer”, etc. under the same ID), we encode all such terms and average their vectors to capture
the broader concept of that job title.</p>
        <p>In cases where the query job title might not have multiple variants (or the variants are essentially the
same phrase), the single phrase embedding is used as-is. After averaging (if applicable), we apply vector
normalization – each query embedding is L2-normalized to unit length. This normalization ensures
that similarity computations are cosine-based and not influenced by vector magnitudes. The output of
this stage is a set of query embeddings (one vector per query job title).</p>
      </sec>
      <sec id="sec-3-6">
        <title>3.6. Embed Skills</title>
        <p>We embed each skill in the skill vocabulary using a similar procedure. For each skill identifier, all alias
phrases from the skill’s entry are encoded via the Sentence-Transformer model, and their embeddings
are averaged to produce one representative vector for that skill. This sentence averaging strategy
leverages the multiple descriptions of a skill to capture its full semantic nuance. For instance, if a skill is
described by the phrases “pricing strategies”, “pricing tactics”, and “pricing plans” in the data, we obtain
embeddings for each of these and then average them to form a single “pricing strategy skill” vector. As
with the queries, we then normalize each skill embedding to unit length. By the end of this stage, we
have a library of skill embeddings (each associated with a skill ID) covering the entire skill vocabulary.</p>
      </sec>
      <sec id="sec-3-7">
        <title>3.7. Cosine Similarity Computation</title>
        <p>With both query (job title) vectors and skill vectors in the same semantic space, we compute pairwise
similarity scores to assess relevance. For each query job title embedding, we calculate its cosine similarity
with every skill embedding. Cosine similarity is used as the relevance metric since it efectively measures
the angular proximity between the normalized vectors.</p>
        <p>
          Given two unit-length vectors, the cosine similarity is equivalent to their dot product, producing
a score in the range [
          <xref ref-type="bibr" rid="ref1">-1, 1</xref>
          ] where 1 indicates identical semantics and 0 indicates orthogonality (and
negative values indicate opposite semantics). In our context, higher cosine scores indicate that the skill
is more semantically related to the job title. This stage takes as input a query vector and iterates over
all skill vectors, outputting a list of similarity scores (one score for each skill) for that query.
        </p>
      </sec>
      <sec id="sec-3-8">
        <title>3.8. Scoring and Ranking</title>
        <p>In the ranking stage, the similarity scores generated for each query are used to produce an ordered
list of predicted skills. For a given job title query, we sort all candidate skills in descending order of
their cosine similarity score relative to the query. This yields a ranked list where the skill with the
highest score is deemed the most relevant skill for that job title, the second highest score is the next
most relevant, and so on.</p>
        <p>We then assign rank positions (starting from 1 for the top skill) to each skill for the query. At this
point, we may also apply a cutof if required by the evaluation (for example, keeping only the top N
predictions or all skills above a certain score threshold), although in our implementation we considered
the full ranking of skills for completeness. The output of this stage, for each query, is a ranked list of
skill IDs accompanied by their similarity scores and rank positions.</p>
      </sec>
      <sec id="sec-3-9">
        <title>3.9. Output – TREC Run File</title>
        <p>Finally, we format the ranked results into the standard TREC run file format for submission. The TREC
format requires six columns per line: q_id, Q0, doc_id, rank, score, and run_tag. In our case, q_id is
the query identifier (the job title ID or query index), and doc_id is the retrieved skill’s identifier. We
populate each line with the query ID, the placeholder “Q0” (required by the format), the skill ID, the
rank (position) of that skill for the query, the similarity score, and a run tag identifying our system.</p>
        <p>An example line would be: "q123 Q0 skill456 1 0.873 run1" indicating that for query q123, the
topranked result is skill456 with a score of 0.873. We include header columns as specified and ensure
the file adheres to the exact formatting guidelines of the competition. The output of this stage is the
completed run file ready for submission and evaluation.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Results and Analysis</title>
      <p>Our system’s performance on the Task B test set was modest but positive. In the oficial Codabench
leaderboard, our run ranked 19th out of 26 participating systems, narrowly outperforming the organizer’s
baseline (which ranked 21st) by two positions. This indicates that our multilingual embedding approach
with synonym augmentation provided a slight improvement over the baseline. We achieved this
improvement without any task-specific supervised training, relying solely on pre-trained mMPNet
embeddings and data normalization. However, the gap between our system and the top performers
remains significant, suggesting there is ample room for improvement.</p>
      <p>To better understand our system’s behavior, we conducted an error analysis on its output. Overall, the
approach performs well on queries where the job title has an unambiguous, specific skill set associated
with it. For instance, given the query “Python Developer”, our model correctly ranks “Python” as a
top relevant skill, along with other highly relevant technical skills like “Software Development” and
“Django”. This suggests that the multilingual SBERT embeddings successfully capture strong semantic
links between well-known technologies and the job title. In such cases, the cosine similarity between
the query and skill embeddings is high for the truly required skills, leading to accurate retrieval.</p>
      <p>
        However, our analysis also revealed several failure patterns. A common issue is the tendency to
retrieve very generic skills at high ranks, even when the job query would require more specialized
expertise. We observed that broad skills such as “Communication Skills”, “Management”, or “Microsoft
Excel” often appear among the top recommendations for many diferent job titles. For example, for the
query “Stock Broker”, the system’s top results included “Sales” and “Communication Skills” – skills
that are indeed relevant but overly general – while more specific finance-related skills like “Financial
Markets” or “Equities Trading” were ranked lower. This bias toward frequent, generic skills is likely
due to the embedding model learning that these terms are semantically related to a wide range of
jobs, thus yielding high cosine similarity for many queries. Anand et al. (2022) encountered a similar
issue: in their results, “Excel” and “Communication Skills” were initially ranked highly for Stock
Broker, overshadowing domain-specific skills [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]. They addressed this by multiplying skill scores
with an inverse document frequency (IDF) factor, which dramatically boosted specialized skills like
“Securities” and “Financial Services” in the ranking. In our current system, we did not implement
such a weighting, which likely explains why generic skills can dominate the results. Incorporating
an IDF-based adjustment or other importance weighting could be a straightforward improvement to
consider, to penalize skills that are ubiquitous across many job titles.
      </p>
      <p>Another class of errors arises from the synonym expansion strategy. While leveraging jobid2terms
and skillid2terms (lists of alternate titles or aliases) generally improved recall, it also introduced noise
in some cases. If a job title’s expanded terms include very broad or ambiguous words, the averaged
query embedding may drift from the core meaning of the job. For example, suppose a query “Marketing
Specialist” is expanded with terms like “Marketing Manager” or “Sales Specialist” from the synonyms
list; the combined representation might lean toward managerial or sales skills that are not strictly
required for the original query. We noticed a few instances where the top-ranked skills seemed more
aligned with a synonym or related concept than with the exact query. This points to a limitation of
averaging embeddings: irrelevant or loosely related synonyms can dilute the representation. A potential
remedy is to weigh synonyms by their relevance or even apply a more sophisticated query expansion
technique.</p>
      <p>
        In summary, our error analysis highlights that while the retrieval approach is conceptually
straightforward but it struggles with distinguishing skill importance and can be influenced by overly general
terms or noisy synonyms. These observations align with findings in related literature and point toward
clear directions for improvement. Incorporating techniques from recent research, such as skill frequency
weighting, task-specific fine-tuning of the embeddings [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ], or even hybrid models that combine text
similarity with graph knowledge [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ], could substantially enhance both the ranking accuracy and the
robustness of our system.
      </p>
    </sec>
    <sec id="sec-5">
      <title>5. Conclusions and future work</title>
      <p>
        The above results and examples underline a key point: our retrieval-based method is easy to implement
and language-agnostic, but it does not capture nuances of skill importance or context as well as
more sophisticated approaches. The lack of fine-tuning or additional modeling means the system
treats the task as pure semantic similarity. This yields reasonable rankings for obvious query-skill
matches, but it fails to diferentiate which skills are truly “required” versus merely related. By engaging
more deeply with related work, we can identify several enhancements. First, moving from a purely
unsupervised approach to a weakly-supervised or fine-tuned model would likely yield significant gains,
as demonstrated by prior studies. Second, introducing an error-correction mechanism or reranker that
accounts for skill frequency could help prioritize niche skills over general ones, similar to how Anand
et al. applied an IDF adjustment [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ].
      </p>
      <p>In conclusion, our participation showed that a straightforward multilingual embedding approach
can serve as a strong baseline, outperforming the provided baseline and validating the feasibility of
language agnostic retrieval for this task. At the same time, the gap between our results and the state
of the art highlights the importance of incorporating task specific insights and training. Future work
should aim to blend the simplicity and coverage of our method with the precision of learned, specialized
models for example, by fine-tuning on job-skill pairs, leveraging contrastive learning with domain data,
and applying post-processing to address the error patterns identified. This combined strategy could
substantially improve the ranking of skills for a given job title, making the system more practical for
real-world talent matching applications.</p>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgments</title>
      <p>We would like to express our sincere gratitude to COTECMAR for providing the necessary space and
resources to carry out this research. We also extend our thanks to the Universidad Tecnológica de Bolívar
(UTB) for ofering the facilities and processing services for running the models, which significantly
contributed to the success of this work. Additionally, we acknowledge the support received through the
"Convocatoria 950" of 2024 sponsored by Minciencias, which provided the resources for the scholarship
that made this research possible.</p>
    </sec>
    <sec id="sec-7">
      <title>Declaration on Generative AI</title>
      <p>During the preparation of this work, the authors used ChatGPT-4, ChatGPT-4o-mini, and o3 AI models
to assist with the enhancement and reorganization of the text. These tools were employed to improve
pragmatic clarity, optimize overall coherence, and ensure consistency in scientific language. Additionally,
DeepL was utilized on certain occasions for translation purposes. Following the use of these tools, the
authors reviewed and edited the content as necessary and take full responsibility for the publication’s
content.</p>
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