=Paper=
{{Paper
|id=Vol-1144/paper8
|storemode=property
|title=Comparison of Fuzzy Membership Functions for Value of Information Determination
|pdfUrl=https://ceur-ws.org/Vol-1144/paper8.pdf
|volume=Vol-1144
|dblpUrl=https://dblp.org/rec/conf/maics/MiaoIHT14
}}
==Comparison of Fuzzy Membership Functions for Value of Information Determination==
Comparison of Fuzzy Membership Functions for Value of Information Determination Sheng Miao and Robert J. Hammell II Department of Computer and Information Sciences Towson University, Towson, MD USA smiao1@students.towson.edu; rhammell@towson.edu Timothy Hanratty Computational Information Science Directorate US Army Research Laboratory, Aberdeen Proving Ground, MD USA timothy.p.hanratty.civ@mail.mil Ziying Tang Department of Computer and Information Sciences Towson University, Towson, MD USA ztang@towson.edu Abstract Recently, a fuzzy associative memory architecture was Network-centric military operations are redefining used to develop a system to calculate VoI in complex information overload as military commanders and staffs are military environments based on the information’s content, inundated with vast amounts of information. Recent source reliability, latency, and the specific mission context research has developed a fuzzy-based system to assign a under consideration (Hanratty, Hammell, and Heilman Value of Information (VoI) determination for individual pieces of information. This paper presents an investigation 2011; Hammell, Hanaratty, and Heilman 2012). Military on the effect of using triangular and trapezoidal fuzzy intelligence analysts were used as subject matter experts to membership functions within the system. provide the fuzzy association rules from which the system was constructed, and preliminary results from the system have been demonstrated and “validated” in principal and Introduction context (Hanratty et al. 2012; Hanratty et al. 2013). Efforts Today’s military operations utilize information from a are continuing towards a more formal validation of the myriad of sources that provide overwhelming amounts of system and to empirically evaluate the effects of the data. A primary challenge of decision makers at all levels system on intelligence analyst performance (Newcomb and is to identify the most important information with respect Hammell 2012; Newcomb and Hammell 2013). to the mission at hand, and often do so within a limited This paper presents an investigation on the effect of amount of time. The process of assigning a Value of using two different membership functions within the Information (VoI) determination to a piece of information fuzzy-based system and a comparative analysis of the has historically been a multi-step, human-intensive differences between them. The paper is organized as exercise requiring intelligence collectors and analysts to follows: the next section presents background information make judgments within differing operational situations. on VoI as well as the design of the original fuzzy system. This is followed by a section that discusses the Research was sponsored by the Army Research Laboratory and was accomplished under experimental framework used for this work, and then a Cooperative Agreement Number W911NF-11-2-0092. The views and conclusions contained in this section describing the experiments and results. The paper document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Laboratory or the U.S. Government. concludes with a section that provides conclusions and The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein. future work. Value of Information (VoI) VoI System While it is likely that numerous characteristics could be In order to turn large amounts of disparate information into applicable to determining VoI, the aspects of source useful knowledge, it is vital to have some way to judge the reliability, information content, timeliness, and mission importance of individual pieces of information; the Value context were used as the starting point to develop an of Information (VoI) metric is used to do this. Ranking the automated VoI system. “value” of information is a formidable task involving not A Fuzzy Associative Memory (FAM) model was chosen only the sheer amount and diversity of information, but to construct the prototype fuzzy system. A FAM is a k- also the idea that the value of a piece of information will dimensional table where each dimension corresponds to likely be influenced by the specific mission context to one of the input universes of the rules. The ith dimension which it will be applied. of the table is indexed by the fuzzy sets that compromise Before going further, it is useful to briefly address what the decomposition of the ith input domain. Fuzzy if-then is meant by information “value”, and differentiate it from rules are represented within the FAM. For the prototype what could be meant by information “quality”. One system, three inputs are used to make the VoI decision: viewpoint is that “quality” refers to the fitness of data with source reliability, information content, and timeliness (how respect to the inherent attributes of the data (accuracy, mission context contributes to the determination will be precision, timeliness, freshness, resolution, etc.) while explained shortly). “value” addresses the utility of the data within a specific The overall architecture of the fuzzy system is shown in application context (Bisdikian et al. 2009). The definition Fig. 1. Instead of using one 3-dimensional FAM, two 2- used in this paper comes from that provided by (Wilkins, dimensional FAMs were used. The reasoning behind this Lee, and Berry 2003). Wilkins considers the practical decision was presented in detail in (Hammell, Hanratty, importance of the information to the receiver, suggesting and Heilman 2012) but essentially it provided a simpler that information with value supports the receiver’s ability knowledge elicitation process, decreased the total number to make informed decisions. of fuzzy rules, and provided a potential for the output of the first FAM to be useful on its own. VoI Determination As seen in Fig. 1, two inputs feed into the Applicability U.S. military doctrinal guidance for determining VoI is FAM: source reliability (SR) and information content (IC); vague at best (US Army 2006; NATO 1997) and does not the output of this FAM is termed the information address integrating mission context into the decision. The applicability decision. Likewise, two inputs feed into the guidance provides two tables for judging the “reliability” VoI FAM: one of these (information applicability) is the and “content” of a piece of data, with each characteristic output of the first FAM; the other input is the information broken into six categories. Reliability relates to the timeliness rating. The output of the second FAM, and the information source, and is ranked from A to F (reliable, overall system output, is the VoI metric. usually reliable, fairly reliable, not usually reliable, The fuzzy rules represented in the FAMs capture the unreliable, and cannot judge). Information content is relationships between the input and output domains. Since ranked from 1 to 6 (confirmed, probably true, possibly both FAMs have two inputs and one output, all the fuzzy true, doubtfully true, improbable, and cannot judge). rules in the system will be of the form "If X is A and Y is B, Doctrinal guidance does not provide any process for then Z is C", where A and B are fuzzy sets over the input combining these determinations into a VoI metric. domains and C is a fuzzy set over the output domain. For Additionally, it is obvious that combining only these two example, an actual rule in the Applicability FAM might be: assessments of a piece of information would fall far short "if Source Reliability is Usually Reliable and Information of representing all the critical aspects for a useful VoI Content is Probably True, then Information Applicability is determination. Two other potential data characteristics include mission context and timeliness. Timeliness relates to how long ago the piece of information was collected, while mission context is set by the operational tempo of the military operation underway. The operational tempo relates to the decision cycle for the mission; that is, the time that can or will be used to plan, prepare, and execute the mission. Fast tempo operations may have a decision cycle measured in minutes to hours, while slower tempo operations may be measured in months or longer. Figure 1. VoI System Architecture Highly Applicable." Knowledge elicitation from military midpoints has been referred to as a TPE system (Sudkamp intelligence Subject Matter Experts (SMEs) was used to and Hammell 1994). Fig. 3(a) shows the TPE construct the fuzzy rules (Hanratty et al. 2012). decomposition of a domain ranging from 1 to 5; Fig. 3(b), Within the Applicability FAM, the two input domains 3(c), and 3(d) illustrate isosceles triangular decompositions (source reliability and information content) are divided into of the same range that do not adhere to the restriction of five fuzzy sets following the guidance provided in (US having bases of the same width. Triangular Army 2006). The omission of the “cannot judge” category decompositions, with and without bases of the same width, from both of the input domains is explained in (Hammell, are included in our experimental framework. Hanratty, and Heilman 2012). The “information In addition to using triangular membership functions, applicability” output domain was decomposed into nine trapezoidal decompositions are another approach we would fuzzy sets (ranging from not applicable to extremely like to explore. Similar to the triangles, isosceles applicable) while the VoI output domain utilized eleven trapezoids both with and without bases of the same width fuzzy sets (ranging from not valuable to extremely are considered. Fig. 5(a) shows the decomposition of a valuable). domain ranging from 1 to 5 using isosceles trapezoids with Up to this point, the contribution of mission context has bases of the same width; Fig. 5(b), 5(c), and 5(d) depict not been apparent. To account for differing mission similar decompositions using isosceles trapezoids without tempos, three separate VoI FAMs were derived to represent the requirement for equally sized bases. three different tempos. Missions were characterized as While we mentioned several forms of membership either 'tactical' (high-tempo), 'operational' (moderate- functions from which to choose, we selected trapezoidal tempo), or 'strategic' (slow-tempo). The system selects the and triangular fuzzy sets for two primary reasons. First, correct VoI FAM based on the indicated mission context, the membership degree calculations for both are linear, thereby utilizing the appropriate fuzzy rule base to produce thereby facilitating high computational efficiency. This is the VoI determination. significant since the purpose of the fuzzy VoI system is to More detailed descriptions of the FAMs, the fuzzy rules help intelligence specialists find the most important bases, the domain decompositions, and other information within a potentially large amount of data while implementation aspects of the prototype system can be frequently adhering to restrictive time constraints. found in (Hanratty et al. 2013). The series of surveys and The second reason is that these two forms can help in interviews with SMEs that were used to integrate cognitive the data acquisition process. As implied earlier, significant requirements, collect functional requirements, and elicit the knowledge elicitation efforts using intelligence specialists fuzzy rules is presented in (Hanratty et al. 2012). as Subject Matter Experts (SMEs) were required to The VoI system has been demonstrated to the SMEs and construct the initial fuzzy rules; likewise, any membership its output has met SME expectations (Newcomb and function optimization will be determined by the SMEs. Hammell 2012). Note that there is no current system The triangular and trapezoidal functions are more visually against which the results can be compared. As such, the understandable and provide an environment more system has not been tested comprehensively due to the conductive to human-in-the-loop knowledge acquisition. human-centric, context-based nature of the problem and Based on these two reasons, trapezoidal and triangular usage of the system. Formal validation of the VoI system membership functions are often used (Zimmerman 1996). requires a comprehensive experiment which is currently To facilitate the analysis of various domain under development separately. decompositions using the triangular and trapezoidal fuzzy sets, we compare them from different aspects and display the results visually. Three categories of experiments are Experimental Framework presented in the next section. First, results from using A major factor in the design of any fuzzy system relates to “standard” triangular and trapezoidal decompositions are the decomposition of the input and output domains into compared, where “standard” means the use of isosceles fuzzy sets. The “shape” of the fuzzy sets defines the shapes with bases of the same width (Fig. 3(a) and 5(a)). membership functions for the system. While there are Next, “standard” triangular fuzzy membership functions numerous shapes for fuzzy sets (triangular, trapezoidal, are compared with “customized” triangular fuzzy Gaussian, bell, and the like), triangular membership membership functions, where “customized” means that the functions were used in the initial VoI system. To further restriction for bases of the same width is removed (Fig. facilitate computational efficiency, it was also required that 3(b), 3(c), and 3(d)). Finally, “standard” trapezoidal fuzzy the triangles were isosceles with bases of the same width; sets are compared with “customized” trapezoidal fuzzy this triangular decomposition with evenly spaced decompositions (Fig. 5(b), 5(c), and 5(d)). Results This section provides the experimental results from comparing triangular and trapezoidal fuzzy set membership functions. Three subsections will be used to present the results. First, a comparison of the “standard” triangular and trapezoidal sets will be shown. Next, several (a) “customized” triangular decompositions will be compared with the initial TPE fuzzy sets. Finally, several “customized” trapezoidal decompositions will be compared with the standard trapezoidal fuzzy sets. Standard Triangular vs Standard Trapezoidal Fig. 2 compares the FAM outputs for the standard (TPE) triangular fuzzy sets (a, c) and the standard trapezoidal fuzzy sets (b, d). Fig. 2a and 2b show the applicability FAM output for the two models; that is, the relationship between source reliability (x-axis) and information content (y-axis). The values of two inputs are from one to five, (b) with the smaller value of one being “better” (better reliability/content) and five meaning “worse” (less reliability/content). The applicability output values vary from one to nine where the larger values represent better applicability; the colors vary from blue to red where the higher value is in blue (high applicability meaning reliable, probable information) and the lower value is in red (unreliable, improbable information). Fig. 2c and 2d show the value of information (VoI) FAM output based on the two inputs of applicability and timeliness. Applicability is as mentioned above. Timeliness reflects the temporal age of the information, with values ranging from one to three: one means “recent” (c) while three means “old”. As with the applicability graphs, the VoI values are represented in the color shades within the graph. The numerical values for VoI range from zero to ten (blue meaning ten; red meaning zero) and the higher values represent higher VoI (more valuable information). The mission context is assumed to be “tactical”. Comparing results for the models, the output landscape of the triangular fuzzy models (a, c) looks smoother while the trapezoidal fuzzy models (b, d) produce some fairly well defined rectangles. To see why, note that when an input (in these standard models) has a membership value equal to 1 in a fuzzy set, the input belongs only to that (d) fuzzy set (see Fig. 3(a) and 5(a)). For example, in the triangular fuzzy model, only the integer input values (1, 2, etc.) belong to just one fuzzy set; that is, there is only one input value in each triangular fuzzy set that will have a membership equal to one. For the trapezoidal fuzzy sets, however, there are several values in each set that have a membership equal to one and, thus, belong to only that fuzzy set. This creates areas within the color graphs that Figure 2. Applicability and VoI: Standard have the same calculated output values for applicability or Triangular and Trapezoidal Fuzzy Sets VoI, thereby producing the more pronounced rectangles. Note these rectangles are seen within the color graph and at the four corners of the graph. Standard Triangular vs Customized Triangular In the experiments shown below, due to space limitations, comparisons between the different models will be (a) illustrated using the results of the applicability FAM only. Fig. 3 and 4 are used to compare the applicability values for the standard and customized triangular fuzzy models; Fig. 3 shows the fuzzy set shapes for all domains in the standard model (3(a)) and the customized models (3(b), 3(c), 3(d)), and Fig. 4 provides the associated color graphs. Case 1 In the standard model, both domains (source reliability and information content) are decomposed following the TPE restrictions as illustrated in Fig. 3(a). The resulting color graph for the standard (TPE) model is shown in Fig. 4(a). In the customized model, both inputs shrink the third fuzzy (b) set from the standard 2 to 4 width (on the x-axis) to the customized width of 2.5 to 3.5 as shown in Fig. 3(b); the corresponding color graph is Fig. 4(b). Compared with the applicability distribution of the standard model, the color graph for the customized model is much less smooth. It is also clear that two very similar color belts cross in the middle of the graph (as outlined); the edges are 2.5 and 3.5 (both vertically and horizontally). The middle of the graph for the customized model has similar color values; however, the outer edge of the color (c) (a) (b) (d) (c) (d) Figure 3. Standard and Customized Figure 4. Applicability: Standard and Triangular Fuzzy Membership Functions Customized Triangular Fuzzy Sets belt has smaller changes than that in standard model and extreme high or low values corresponding to dark blue and the inner edge has larger changes which cause the visible dark red. boundaries. Also, four rectangles in a solid color around the center are observable (and outlined) in Fig. 4(b). The Standard Trapezoidal vs Customized Trapezoidal reason for the observed differences is that in the Fig. 5 and 6 are used to compare the applicability values customized model, inputs between 2 to 2.5 and 3.5 to 4 for the standard and customized trapezoidal fuzzy models; only belong to one fuzzy set. This leads to smooth Fig. 5 shows the fuzzy set shapes for all domains in the visualization and solid squares of the same color. On the standard model (5(a)) and the customized models (5(b), other hand, input values between 2.5 to 3.5 belong to two 5(c), 5(d)), and Fig. 6 provides the associated color graphs. fuzzy sets. The third fuzzy membership degree is changed Case 1 faster (narrower triangle; slope is larger) than that in the In the standard model, both domains (SR and IC) are standard model. As a result, this enhances the decomposed as illustrated in Fig. 5(a). The resulting color representation of boundaries. graph for the standard model is shown in Fig. 6(a). In the Case 2 customized case, the middle fuzzy set is still an isosceles In this case, the third fuzzy set is assigned a wider range, trapezoid but the width is smaller than the other sets, as encompassing the entire input domain, as shown in Fig. depicted in Fig. 5(b). The left and right bottom points are 3(c). Again, in the standard model both domains are 2.5 and 3.5; note the upper base is the same 2.75 to 3.25 as decomposed following the TPE restrictions (3(a)). in the standard trapezoidal model. The corresponding color The values in the customized color graph in Fig. 4(c) graph is shown in Fig. 6(b). look smoother in the center with sharp variations occurring As in Case 1 of the triangular fuzzy model, the color in red and blue at the corners; the red and blue corner graph for this customized trapezoidal model illustrates two values have a much smaller area than in the standard fuzzy similar color belts crossing in the middle of Fig. 6(b). triangular model. The reason is that the third fuzzy set in Because the middle fuzzy set is narrower and more inputs the customized model affects all the fuzzy membership belong to only the second or fourth fuzzy set, the edges degree calculations since it spans the entire input domain. corresponding to the middle SR and IC input values are For high value inputs, the third fuzzy set causes lower smaller and more pronounced than those of the standard FAM values to join the calculation, resulting in a lower trapezoidal model in Fig. 6a. Also, the neighboring output value than that in the standard model. rectangles of solid color are larger than that in the standard The reverse occurs for the low value inputs; the middle model. Note that the areas associated with the four corners fuzzy set contributes higher FAM values to the are similar in both the standard and customized color applicability result. Thus, the red and blue boundaries graphs. contract to the corners of the customized graph as Case 2 compared to the standard triangular fuzzy model results. Considering the opposite setup with the middle fuzzy set as Case 3 shown in Fig. 5(c), this case sets the middle fuzzy set to Considering that some users maybe prefer a wide range in cover a wider input range, from 1 to 5. However, the upper the middle fuzzy sets (most IC and SR inputs would fall in base is still fixed from 2.75 to 3.25 and all other sets are the “middle”) but smaller ranges at the edges (only the same as in the standard trapezoidal model. extreme IC and SR inputs are considered “best” or Fig. 6(c) illustrates the associated color graph. The result “worst”), Fig. 3(d) shows a fuzzy set pattern to provide of the customized trapezoidal model reveals a similar trend such a system. In this model, the two ends are made as that of the corresponding triangular model; more areas narrower (range from 1 to 1.5 and 4.5 to 5), which means in the middle values can be observed and sharp variation only a small range of inputs belong to these sets. The happens in the corners as compared to the standard middle set has a wide input scope, which is from 1.5 to 4.5. trapezoidal model in Fig. 6(a). Nevertheless, the graph still Meanwhile, the input ranges of other two fuzzy sets are presents the basic features of the trapezoidal fuzzy model - reduced appropriately. some rectangles in similar colors exist in the color graph Fig. 4(d) shows the applicability distribution based on which are not as obvious in the triangular fuzzy model. this customized model which is much more “blocky” than Case 3 that of the standard TPE model shown in Fig. 4(a). Based on the same scenario as with Case 3 for the Because the middle fuzzy set is extended and covers triangular fuzzy sets, this customized trapezoidal model numerous inputs, the resulting output has a number of sets up a wide middle fuzzy set and narrower side sets as areas in the middle values. The contraction of the other shown in Fig. 5(d). In this setup, only very high or low fuzzy sets causes much of the graph area to show up in the value inputs are regarded as extreme conditions. orange and cyan colors, while only the corners have (a) (a) (b) (c) (b) (d) Figure 5. Standard and Customized Trapezoidal Fuzzy Membership Functions Fig. 6(d) shows the applicability distribution based on the customized model. Compared with the result of the standard trapezoidal fuzzy model in Fig. 6(a), similar results occur as with Case 3 for the triangular model. The areas in the middle values are larger than those in the standard trapezoidal model (Fig. 6(a)) and only small (c) sections of dark red and blue in the corners represent the extreme high and low applicability values. Moreover, the result of this customized model retains the features of a trapezoidal fuzzy model which produces larger areas in the graph of solid colors. However, one difference is that color boundaries between the rectangles are much narrower in the customized model. This makes the boundaries more pronounced and provides well-defined solid color rectangles. Conclusion and Future Work (d) This paper presents two approaches for codifying the contextual underpinnings (framework) and cognitive interpretation for capturing VoI utilizing source reliability, information content and latency based on triangular and trapezoidal fuzzy membership functions. While both approaches for capturing VoI are intuitively simple to comprehend and computationally easy to calculate, differences are observed. The first major difference observed is that when using Figure 6. Applicability: Standard and the triangular approach the results of the color graphs were Customized Trapezoidal Fuzzy Sets strikingly different than those of the trapezoidal approach. performance of data fusion systems. In Handbook of Multisensor Using the triangular fuzzy model produced graphs that Data Fusion, D. Hall and J. Llinas (Eds.), CRC Press, Boca Raton, FL, 2001. were infinitely smoother in their transition between Hammell II, R.J.; Hanratty, T.; and Heilman, E. 2012. Capturing calculated values. The trapezoid models, on the other the Value of Information in Complex Military Environments: A hand, produced plots that appeared “blockier”, lending to Fuzzy-based Approach. In Proceedings of the 2012 IEEE larger areas of continual homogeneous values. International Conference on Fuzzy Systems (FUZZ-IEEE 2012) A second major difference observed is the increased as part of the 2012 World Conference on Computational flexibility for representing membership functions afforded Intelligence (WCCI 2012), 142-148. Brisbane, Australia. by the trapezoidal representation. Using the trapezoids Hanratty, T.; Hammell II, R.J.; Bodt, B.; Heilman, E.; and allowed an ‘interval of values’ that maximized the Dumer, J. 2013. Enhancing Battlefield Situational Awareness Through Fuzzy-based Value of Information. In Proceedings of individual membership functions (top of the trapezoids) as the 46th Annual Hawaii International Conference on Systems compared to the triangle representation that permitted only Sciences (HICSS 2013), 1402-1411. Maui, Hawaii. one. The introduction of the trapezoid dramatically Hanratty, T; Heilman, E; Dumer, J.; and Hammell II, R.J. 2012. increases the ability of the user to capture representations Knowledge Elicitation to Prototype the Value of Information. In over the more simplistic triangular shape. Proceedings of the 23rd Midwest Artificial Intelligence and With this understanding, one might mistakenly chose Cognitive Sciences Conference (MAICS 2012), 173-179. Cincinnati, OH. one approach over the other, thinking on one hand the trapezoidal approach is inferior because of the “blocky Hanratty, T.; Hammell II, R.J.; and Heilman, E. 2011. A Fuzzy-Based Approach to the Value of Information in Complex effect” or on the other hand superior because of the added Military Environments. In Proceedings of the Fifth International flexibility. The fact is both approaches have their own Conference on Scalable Uncertainty Management (SUM 2011). strengths and weaknesses. For example, depending on the Dayton, OH. context of the situation, the blocky effect might provide a North Atlantic Treaty Organization (NATO). 1997. Standard better representation of the military function being Agreement (Edition 8) Annex. modeled. An example of this effect can be seen when Newcomb, A.; and Hammell II, R.J. 2013. Validating a Fuzzy- comparing a logistic battle function against that of a based Mechanism for Improved Decision Support. In tactical combat battle function. For the logistics operations Proceedings of the 14th IEEE/ACIS International Conference on Software Engineering, Artificial Intelligence, Networking and the fidelity of the information required for moving Parallel/Distributed Computing (SNPD 2013), 143-148. equipment can be significantly less critical than that Honolulu, Hawaii. required when conducting a combat cordon and search Newcomb, A.; and Hammell II, R.J. 2012. Examining the operation; as such, the logistical representation of VoI may Effects of the Value of Information on Intelligence Analyst very well be represented with larger areas of homogeneous Performance. In Proceedings of the 5th Annual Conference on values (blocking effect). Information Systems Applied Research (CONISAR 2012). New Orleans, LA, http://proc.conisar.org/2012/pdf/2227.pdf. Ultimately the goal of this research is targeted to improve the higher-level information fusion process (Hall, Sudkamp, T. and Hammell II, R.J. 1994. Interpolation, Completion, and Learning Fuzzy Rules. IEEE Transactions on Hall, and Tate 2001) - effectively interleaving the human Systems, Man, and Cybernetics, 24-2:332-342. computer interaction (HCI) with the lower-level fusion US Army 2006. US Army Field Manual (FM) 2-22.3, Human process. To accomplish this goal further refinement of the Intelligence Collector Operations. VoI approach is necessary and includes the following Wilkens, D.E., Lee, T.J., and Berry, P. 2003. Interactive activities: 1) vetting the VoI approaches with subject execution monitoring of agent teams. Journal of Artificial matter experts to provide direct feedback on applicability, Intelligence Research (JAIR), 18:217-261. 2) exercising the VoI construct within a task network Zimmermann, H.J. 1996. Fuzzy Set Theory and its Applications model to assess the potential impact, and 3) conducting (Third edition). Boston/Dordrecht/London: Kluwer Academic human-in-the-loop experiments to measure how Publishers (1996) ISBN 0-7923-9624-3. cognitively aligned interfaces improve task performance. References Bisdikian, C., Kaplan, L. M., Srivastava, M. B., Thornley, D. J., Verma, D., & Young, R. I. 2009. Building principles for a quality of information specification for sensor information. In 12th International Conference on Information Fusion. Seattle, WA. Hall, M. J., Hall, S.A., and Tate, T. 2001. Removing the HCI bottleneck: How the human-computer interface (HCI) affects the