Changes in information source preference of managers over the decades

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Changes in information source preference of managers

over the decades

Lucas O. Meertens

[email protected]

ABSTRACT

Behaviour of managers has been a long–standing subject for research. One of their main assets is their ability to acquire and make use of information. Still research on information behaviour of managers is limited compared to many other groups. This article presents a literature review of studies conducted on the information source preference of managers over the past 50 years. The main objective was to discover which information sources managers prefer and how recent changes have affected this. It is shown that their prefer-ence depends on the situation: when there is high ambi-guity, managers will choose source with higher information richness, such as oral communication. While in case of low ambiguity they prefer source with lower ambiguity, such as written media or information systems. A shift from total preference for oral communication to the above was first recorded in 1987.

Keywords

information source preference, managers, management in-formation, information management, information behaviour

1. INTRODUCTION

Although processing of information is not a goal of man-agement, it is a key part in the managers job; around forty percent of their time is spent on it [Min89]. They especially need information to make decisions, and the quality of their decisions may be directly related to the quality of the in-formation [OI82]. In the current inin-formation era managers have access to continuously growing amounts of data, deliv-ered by both traditional sources and new technologies such as Management Information Systems, Decision Support Sys-tems and the World Wide Web. Too much information leads to the phenomenon of information overload [Tof71] [vR06]. Other situations still show lack of information or even incor-rect data. Given the ever present changing environment of organizations designers of new information systems must be aware of what managers need and how they want it served

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to them. Looking back at the previous transformation of the managers’ preferences and applying information behaviour theories, better information systems could be developed. Successful managers must have some way to get exactly the information they need to make the right decisions. Where and how do they retrieve it?

2. SCOPE

The literature review reveals that, relative to the large num-ber of studies available on other professionals such as en-gineers and scientists, the number investigating the infor-mation behaviour of managers as a distinct group is rela-tively low. Further, the number of studies focusing on source preferences offer very limited insights on managers and are mainly concentrated on engineers, social scientists, R & D personnel and other professionals. The objective of this re-view is to analyse relevant studies and trace how managers choice of source preferences for acquiring information has been transformed over the decades. The research is limited to the past 50 years, as no earlier data is available and takes any kind of manager into account, where a manager is de-fined as a person in charge of a formal organization or its subunits [Min73]. Individual differences between managers, such as managerial roles and levels, are not taken under consideration in this review.

3. METHODOLOGY

The research is based on multiple prior studies on infor-mation behaviour theory on one side and prior studies, in-cluding surveys, case studies or interviews, about manager information source preference on the other side. This non– reactive approach has mainly been chosen as literature was found that already describes the search behaviour of man-agers in both the past [CST56] and present [Mac05], en-abling a reconstruction of the changes from the 50’s until now. Information behaviour theories are also abundantly available.

The studies were collected by searching available on-line databases. These were Google Scholar, IngentaConnect and the ACM Guide. The latter two were selected based on [SR04], which states that these two together cover all 25 top IS journals. Google Scholar was selected after searches in the other databases delivered little recent results on the subject. Articles in the proceedings of former TSConIT were also searched. The search terms used can be found in table 2. The search terms were used in multiple manners: with and without “manager” and “management” as addition and, for terms consisting of more than one word, as complete

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Table 1: Search terms information behaviour information source preference source preference

information search behaviour search behaviour

information seeking behaviour seeking behaviour

information search theory search theory

information source source of information information channel

information delivery mechanisms concept of information

acquire information information choice data collection technique decision making

information needs information retrieval

human information behaviour knowledge management

string and as loose words with the use of an AND-operator. Where applicable both the UK and USA alternatives were used, e.g. behaviour and behavior. IngentaConnect and the ACM Guide were first searched and Google Scholar later on. Of the articles found in each search only the top 40 in rele-vance according to the search engine were considered. These top 40 were scanned for actual relevance and relation to the subject. Forward and backward citation searches were done on the resulting selection, with the same relevance demands as before. The result of this recursive process was filtered. For the literature on managers information source preference the two main criteria were that the study should directly be based on actual field work and of course that this field work was conducted on managers. Other intended, possibly inter-esting filters such as age, gender, geographical location and manager level were discarded. For literature on information behaviour theory the amount of citations was taken to see if the work was seminal. Regrettable extra criteria were that the material would have to be available either on-line or in the University of Twente library and for the language to be English or Dutch to ensure access.

4. RESEARCH OBJECTIVE

Although a lot of research has been conducted on informa-tion behaviour, only few studies look at the managers as a separate group. Most research was on specialists, e.g. vet-erinarians [Wal00], and students [Por06]. On the other hand theories are available on how people in general should search for information. Zipf [Zip49] stands at the root of these the-ories with his principle of least effort, but many more have been described since.

This research aims to discover how managers actually search for information and see how developments have affected this over time. The theories on information behaviour can then be fitted to the managers. Additionally the results might be used to check on the effectivity of information systems

and possibly improve their design by better customization to the managers needs.

In short we are trying to discover if the manner in which managers acquire information has been altered.

4.1 Hypotheses

H1: ICT has increased the quantity of information sources, but not their quality.

Two hypotheses were thought of. The first hypothesis han-dles the increase in use of information technology. As time progresses, more and more technologies were developed to provide data to managers. Many new systems only man-age to deliver data and not real information. This leads to a high quantity of data for managers, but does not improve the quality of the information. This may result in information overload, as the manager needs to process large amounts of information while only little of it is actually useful to him. If, however, the hypothesis is false and the quality of infor-mation sources and the resulting inforinfor-mation is improved due to use of information technology, then the working en-vironment for managers is improved.

H2: Managers still trust and depend on personal contact for information.

The second hypothesis reflects the manner in which man-agers truly acquire their information. If it proves to be false, then a lot seems to be changed over the past few decades, since Mintzberg found: “Managers strongly favor the oral media” [Min89]. It would justify the use of information technology for gathering and distributing information in or-ganisations. In case the amounts of data are so large that managers leave the progressing of it to their subordinates and depend on their view of it, the hypothesis will be false. Both hypotheses were expected to be true before starting the research, showing a distrust of information technology in organisations.

5. RESULT

5.1 Information theories over the decades

According to Zipf’s [Zip49] first theories managers (and peo-ple in general) try to acquire information according to the “Law of Least Effort”. This law insinuates that the quality of information is sacrificed to the cost of getting it. This theory stood all alone for more than a decade, when in 1961 the first reference [Sti61] was made to a second model: cost– benefit, according to which people will balance the costs (time and effort) of acquiring the information to the bene-fits (such as quality) of using a selected source.[Har82] These models are supported by several studies that proof both can be right under certain circumstances. Those early studies are disputed though, due to lack of external validity [OI82]. In 1983 the term “information richness” was coined [DL83]. If information is considered “rich” depends on feedback im-mediacy, cue/channel capacity, language variety and per-sonal focus. These order information from face–to–face con-tact (rich) to numeric documents (poor) [DL86]. This theory sets any information from technology as being low in rich-ness.

As the internet started to develop so did more detailed mod-els of information behaviour. Wilson’s model in figure 4.1 incorporates all the new variables in the stages of informa-tion behaviour. In the 1990’s more atteninforma-tion was given to

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Figure 1: Information Behaviour Model of Wilson

the individual environments of people, which is now thought to have a significantly greater impact on source preference than any other factor, such as source quality. Numerous studies were done on the usage of the world wide web to retrieve information, confirming it’s ease of use, but also the lack of quality inherent to such open network. In combi-nation with the enormous amount of times it is used, this seems to be confirming Zipf’s law of least effort again.

5.2 Information behaviour model

Many different information behaviour theories can be found. Recently Wilson has summarized and combined some of the older models, such as Ellis’, Kulhthau’s and his own, to form a new model that tries to cover the steps and theory of all those before. This is the model shown in figure 4.1. The model deals with all three levels of information behaviour shown in figure 5.1 [Wil99]. In short information behaviour is the totality of human behaviour in relation to sources and channels of information, including both active and pas-sive information seeking, and information use. Information seeking behaviour is the purposive seeking for information as a consequence of a need to satisfy some goal. Informa-tion searching behaviour is the micro-level of behaviour em-ployed by the searcher in interacting with information sys-tems of all kinds. It consists of all the interactions with the system [Wil00]. For this research the information seek-ing behaviour is of greatest interest as it defines the actual information sources and the manner in which managers use these sources. On the other hand the activating mechanisms are considered as they point out why managers use certain

sources. This is an area on which most of the information behaviour research only speculates, even if it is based on field research.

A special note should be made on Nied´zwiedzka, who identi-fied the lack of a proper model to research the specific infor-mation behaviour of managers as a group during a study not specified on them, and later proposed such a model [Nie03]. This model is not applied to this study as it lacks the amount of citations that Wilson’s model has.

5.3 Search results

Although the preliminary literature review seemed promis-ing, only very few published case studies on managers’ infor-mation source preferences could be found. The total selec-tion of was made up of eleven articles, from 1956 till 2004, with most accumulated in the eighties and at the start of the millennium. They are listed in table 5.2 and described chronologically in the rest of this section. The earliest works of interest were based on observations as opposed to the sur-veys conducted in almost all later field research.

The oldest study was published in 1956 and covered the ob-servation of a single American manager during a large, un-programmed decision over three and a half years. Managers’ information behaviour was covered as part of the decision progress. It found that the manager got most of his informa-tion from his subordinates and let them filter it. Although the study covered multiple smaller decisions as part of the total, it observed only a single manager and thus the valid-ity is disputable. [CST56]

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Table 2: Reviewed papers

Year Authors Sample

size

Method Findings

CST56 1956 Cyert, Simon, 1 observation subordinates for filtering

Trow subordinates principal source

Min68 1968 Mintzberg 5 structured obser-vation

78% time spent on oral communication

OI82 1982 O’Reilly III 163 survey more use of high quality info most use of accessible info AQ83 1983 Alloway, Quillard 529 survey 79% of systems TPS

only 44% of systems are used by managers non-TPS systems are almost all appropriate a bad source might be the only source many (important) needs are not supported DLT87 1987 Daft, Lengel, 95 interviews rich media used in case of high ambiguity

Trevino incident collection poor media in case of low ambiguity media selection for

incidents

disagrees with oral for all cases

FDY88 1988 Ferratt, Dunne, Young 49 survey (self review instrument)

(middle) managers should use IT

AC94 1994 Austin, Choo 13 interviews use of multiple sources (2-5)

incident collection personal for competitors and customers (CIT) written for regulations and technology CDT00 2000 Choo. Detlor, Turnbull 34 survey web is mostly used for informal search, but

web log for other searches too though interviews

dAH01 2001 de Alwis, Higgins 20 survey oral media for competitor trends written for most other

little use and low satisfaction with IT Mac03 2003 Mackenzie 50 survey acquiring data that is not necessary

mapping not always look for colleague for information interviews relationship is important

VFK04 2004 Vlahos, Feratt, 117 survey higher level means less computer use

Knoepfle prefer simple (IR) over complex (DSS)

Mintzberg’s first work was the basis for his later successes. For his study published in 1968 he had observed five CEO’s of large American companies for five days each using the method of structured observation. The use of this method was later both criticized and supported. The main findings in relation to this research are the huge amount of oral com-munication (78% of their time) and their view of written communications as a burden to be disposed of. [Min68] In the seventies the research on managers information be-haviour appears to have dropped, and although Mintzberg published several books and articles in this period they were based on his earlier research. The first applicable study found was by O’Reilly, published in 1982. It covered the im-pact of quality and accessibility of information on the choice of information sources. The research was done by means of survey in 39 business units spread over 4 branches. 163 of 190 people replied to the survey. They were given only a limited amount of sources they could choose from. The re-sults indicated that managers make more use of high qual-ity information sources than lower qualqual-ity sources, but that accessibility was the main reason to use a specific source. [OI82]

As computers started to appear in everyday business use, re-search was conducted to find what managers actually used and what they wanted out of this new technology. In 1983

Alloway and Quillard published their findings on this subject as side effect of a larger survey. The survey they conducted was among middle managers and with 529 out of 1058 peo-ple replying it is the largest study covered by this literature review. Regretfully this study was limited by the fact that it was specific for computer usage. It found that at this time most (79%) “information systems” were Transaction Pro-cessing Systems (TPS). Of all systems only 44% were used by managers, which found most non-TPS to be appropriate. They still used TPS to acquire their information, as this bad source of information was still often the only source. Many managers reported that their more important needs were not supported by systems and that too few systems were tailored for managers specifically. The study concluded that “man-agers need information, not computers”. [AQ83]

In 1987 a thorough study was published on information am-biguity, manager performance and their source preference in relation to information systems. The field research, which was part of a larger study in a petrochemical company, con-sisted of interviews, incident collection and a survey to find source preference for each group of incidents. The survey was conducted under 95 people who had not participated in the earlier parts. The research was limited by the fact that no “new media” were included. The study was the first to counter the traditional believe that managers always prefer

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Figure 2: A nested model of the information seeking and information searching research areas

oral communication over other sources of information. It was found that although in cases of high ambiguity good managers prefer rich media, such as oral communication, they prefer low richness, such as written sources, when the ambiguity is low (programmed decisions). On the subject of manager performance it was shown that managers with more source sensitivity out performed those with less source sensativity. [DLT87]

Giving a balanced view of the aversion of computer use by managers at the time is a survey using a “self review in-strument” was held with the focus on personal computer usage among high computer use managers in 1988. The self review was completed by 49 managers in nine mid west companies. Validity is limited by the selection of managers who use computers a lot. It was concluded that (middle) managers should use the personal computer. On a side note most managers did not expect to loose their secretaries due to the increased use of computers, but said loosing them would not be a bad thing. [FDY88]

Austin and Choo publish their research on environmental scanning by Canadian CEO’s of publishing and telecommu-nication companies in 1994. It was conducted by both inter-views and critical incident collection among thirteen CEO’s in Ontario. They focussed on information collection in en-vironmental scanning, which limits the general applicability to managers’ information behaviour. It was found that the CEO’s generally used multiple (two till five) sources when scanning the environment. As Daft et al. in 1987 they found that managers actually prefer written media for some purposes: regulations and technological innovations were ac-quired by those media. Customer and competitor informa-tion was acquired by personal communicainforma-tion. [AC94] A more recent study also by Choo, this time in cooperation with Detlor and Turnbull, focusses on use of the web as an information source by both managers and professionals. The field research consisted of a survey and interviews with 34 people, in combination with two weeks of web logs on each of

these people. It was theoretically supported by Ellis’ model of information behaviour. As the study was limited to web usage and did not differentiate between managers and pro-fessionals, it has only limited value to the review. It was found that most information seeking done on the web is in-formal. [CDT00]

Focussing on information as a tool in the decision process, a study was published in 2001 that was based on a sur-vey among practising members of the Singapore Institute of Management. Of the 369 people contacted, only twenty replied with a filled questionnaire. As with Austin and Choo in 1994 it was found that oral communications is preferred to acquire information on competitors and that written in-formation is sufficient for most other areas. In addition an unexpected low use of modern information technology was recorded. And when it was used it often resulted in low sat-isfaction. [dAH01]

In a three part study Mackenzie published her dissertation in 2003. Although she published more articles in more re-cent years, as with Mintzberg, these were based on field research conducted for and reported in this study. She used surveys with fifty line-managers (two or more subordinates) and a reference group of fifty non-managers of a single busi-ness unit of a large American corporation. She applied so-cial mapping and finally conducted interviews with the five line-managers that had most information coming in an go-ing out accordgo-ing to the resultgo-ing map. A new information behaviour model was build to fit the findings of the study. Limitations to this study lie in the fact that only a single business unit has been sampled and that the focus was on managers as an information source themselves. According to this study managers acquire a lot of unnecessary data, which is why they make good information sources. It was concluded that managers do not always turn to the source with the highest quality, but most often the choise is made on basis of personal relation. [Mac03]

The most recent article reviewed for this study was pub-lished in 2004. It describes the use of Computer Based Information Systems (CBIS) by German middle and top managers. The field research consisted of a survey which was mailed to a randomly selected sample of thousand man-agers, of which 117 replied. The main limitation of this study for the review is the consideration of any CBIS. It was discovered that higher level managers used less CBIS than lower level managers. The finding of most interest to this review was the reported preference of the simpler Informa-tion Retrieval Systems to the more complex, but also more flexible Decision Support Systems. Both points mentioned above could be explained by the 1987 study that stated for cases with more ambiguity managers would prefer rich me-dia, oral communications. Assuming that higher level man-agers cope more with those cases and that DSS are supposed to be designed for those complex cases. Another interest-ing thinterest-ing was that almost 69% of the respondinterest-ing German managers indicated that the CBIS most important to them was developed to support the informational needs of man-agers (decision makers) instead of another purpose. This is in agreement with the lack of such systems that Alloway and Quillard reported more than 20 years earlier. [VFK04]

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6. DISCUSSION

6.1 H1: ICT has increased the quantity of

in-formation sources, but not their quality.

As reported by Vlahos et al., simple Information Retrieval Systems seem to have a higher added value for managers than the more flexible Decision Support Systems. This is in contrast with the conventional idea of Alloway and Quil-lard that managers would prefer flexible inquiry and analysis systems to those spawning standard reports. This would ei-ther point out that high–tech systems are still limited in the quality of information they provide, or that Zipf’s law of least effort again comes into play and managers just want to find their numbers on their desktop (and disregard them) instead of having to query themselves. It can also be seen as a need for poor, but accurate information by managers: richness might be more important than quality in certain situations, but not in others. This is supported by Daft et al. who found that when more ambiguity existed, managers would turn to richer media, while for standard situations poor information was preferred. The reported preference of the simpler Information Retrieval Systems to the more complex, but also more flexible Decision Support Systems (DSS) seems to point out that a DSS falls in–between those cases. Further it was found by Ferratt et al. that (mid-dle) managers would have to make use of the information technologies. This is also supported by Alloway and Quil-lard who noted that managers often have to make use of systems that were not designed for them, but were their only source of the required information. While two studies showed that managers were actually satisfied with the infor-mation systems that were specifically designed for managers, one showed that information technology in general was only used sparsely and with low satisfaction.

From the above can be concluded the quality of simple, manager specific information systems is high enough, but the obligatory use of non–tailored systems results in an un-wanted increased quantity of information sources, with a too low quality at average. The quality of information sources has increased, but so has the quantity. As the latter seems to have increased more, the hypothesis is concluded to be true.

Table 3: Agreement with hypotheses

Paper H1 H2 CST56 ++ Min68 ++ OI82 – ++ AQ83 +/– DLT87 – – FDY88 – – – AC94 – –/+ CDT00 – dAH01 ++ –/+ Mac03 ++ VFK04 +/– +/–

6.2 H2: Managers still trust and depend on

personal contact for information.

According to all three of the earliest studies reviewed, man-agers had a great preference for oral communications, with

no exception for any cases. They would especially use their subordinates to filter information and use most of their time with oral communication. With the idea of information rich-ness arising in the eighties, it was found that the information source managers choose was actually dependent of the sit-uation. In cases of low ambiguity information sources with low richness were preferred to those of high richness. This shift was supported by almost all later studies. Only the one by Mackenzie shows great preference for oral communi-cation. On the other hand only the study specified on the web by Choo et al. makes no comment on the use of oral communication at all. The other studies all show a balance between oral communication and the use of written or elec-tronic sources of information. Noteworthy may be still be what Vlahos et al. found: higher level managers tend to make less use of information systems than lower level man-agers.

The hypothesis is true, as in cases of high ambiguity man-agers still prefer oral communication (sources of high infor-mation richness). It must also be mentioned though, that sources with low richness seem to be invaluable too for those cases of low ambiguity.

6.3 Future research

A great gap in published research seems to exists in the area of information behaviour of managers. Most researchers that handle the subject often refer to their own experience as a manager rather than data gained with field research. Others base a great deal of their theories on limited field research. To fill the gap, relative simple field research on the informa-tion search behaviour of managers could be done to discover their information source preferences. Replicating the field research of Vlahos et al. in other areas or more specified may make a good start. Following research could be taken to the next level of Wilson’s model (see figure 5.1), supple-menting it with the whole area of information behaviour of managers). When doing this research it should be taken into account that most research until now either had a very lim-ited sample size or was founded on a survey which had only a small (approximately 5%–10%) return rate if it was not in conjunction with another project. These are both pitfalls for future research. Triangulation as done by Mackenzie and Daft et al. can lead to more accurate results.

7. CONCLUSION

Managers use information systems as sources of informa-tion, as well as other media with low information richness. These information systems are only their preferred choice in situations with low ambiguity though. Almost all reviewed studies show the preference for richer media, especially oral communication, in cases of high ambiguity. A shift from total preference for oral communications to the above situa-tion was recorded in the eighties. An informasitua-tion system de-signer should take the different source preference at different levels of ambiguity into account. And the higher satisfac-tion of managers with systems actually build for managers, as opposed to those they must use, but were tailored for an-other purpose. Finally, managers should be aware of their own source preferences, as it was shown that those choosing their sources better, also made better managers.

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8. REFERENCES

[AC94] E. Auster and C.W. Choo. How Senior Managers Acquire and Use Information in Environmental Scanning.Information Processing and

Management, 30(5):607–618, 1994.

[AQ83] R.M. Alloway and J.A. Quillard. User Managers’ Systems Needs.MIS Quarterly, 7(2):27–41, 1983.

[CDT00] C.W. Choo, B. Detlor, and D. Turnbull. Working the Web: an empirical model of Web use.System Sciences, 2000. Proceedings of the 33rd Annual Hawaii International Conference on, page 9, 2000.

[CST56] R.M. Cyert, H.A. Simon, and D.B. Trow. Observation of a Business Decision.The Journal of Business, 29(4):237–248, 1956.

[dAH01] S.M. de Alwis and S.E. Higgins. Information as a tool for management decision making: a case study of Singapore.Information Research, 7(1):7–1, 2001.

[DL83] R.L. Daft and R.H. Lengel.Information Richness; a New Approach to Managerial Behavior and Organization Design. Texas A&M University, 1983.

[DL86] RL Daft and RH Lengel. Organizational information requirements, media richness and structural design.Management Science, 32(5):554–571, 1986.

[DLT87] R.L. Daft, R.H. Lengel, and L.K. Trevino. Message Equivocality, Media Selection, and Manager Performance: Implications for Information Systems.MIS Quarterly, 11(3):355–366, 1987.

[FDY88] TW Ferratt, EJ Dunne, and S. Young. Managers who personally use information technology frequently: a profile of some invisible computer personnel.Proceedings of the ACM SIGCPR conference on Management of information systems personnel, pages 120–127, 1988. [Har82] A.P. Hardy. The Selection of Channels When

Seeking Information: Cost/Benefit vs. Least-Effort.Information Processing and Management, 18(6):p289–93, 1982.

[Mac03] M.L. Mackenzie.The Accumulation of Information by Line Managers Within a Business Environment and the Resulting Cognitive Savings Account. PhD thesis, Long Island University, 2003.

[Mac05] M.L. Mackenzie. Managers look to the social network to seek information.Information Research, 10(2):paper 216, 2005.

[Min68] H. Mintzberg. The manager at work; determining his activities, roles, and programs by structured observation. 1968.

[Min73] H. Mintzberg.The nature of managerial work. Harper & Row, 1973.

[Min89] H. Mintzberg.Mintzberg on management: inside our strange world of organizations. Free Press New York, 1989.

[Nie03] B. Nied´zwiedzka. A proposed general model of information behaviour.Information Research, 9(1):9–1, 2003.

[OI82] C.A. O’Reilly III. Variations in Decision Makers’ Use of Information Sources: The Impact of Quality and Accessibility of Information.The Academy of Management Journal, 25(4):756–771, 1982.

[Por06] N.O. Pors. The public library and students’ information needs.New Library World, 107(7/8):275–285, 2006.

[SR04] R.B. Schwartz and M.C. Russo. How to quickly find articles in the top IS journals.

Communications of the ACM, 47(2):98–101, 2004.

[Sti61] G.J. Stigler. The Economics of Information.The Journal of Political Economy, 69(3):213–225, 1961.

[Tof71] A. Toffler.Future shock. Bantam Books New York, 1971.

[VFK04] George E. Vlahos, Thomas W. Ferratt, and George Knoepfle. The use of computer-based information systems by german managers to support decision making.Inf. Manage., 41(6):763–779, 2004.

[vR06] G.J. van Roekel. Information overload: causes and solutions in management information systems. InProceedings of 5th Twente Student Conference on IT, 2006.

[Wal00] T. Wales. Practice makes perfect? Vets’ information seeking behaviour and information use explored.Aslib Proceedings, 52(7):235–246, 2000.

[Wil99] T.D. Wilson. Models in information behaviour research.Journal of Documentation,

55(3):249–270, 1999.

[Wil00] T.D. Wilson. Human information behavior.

Informing Science, 3(2):49–55, 2000.

[Zip49] G.K. Zipf.Human behavior and the principle of least effort. Addison-Wesley Press Cambridge, Mass, 1949.