PhD defense: Trond Vegard Johannessen

PhD Defense

5 June 2015 21:35

(updated: 7 March 2016 21:38)

PhD defense: Trond Vegard Johannessen

On Thursday 18 June 2015 Trond Vegard Johannessen will hold a trial lecture on a prescribed topic and defend his thesis "Data presentation formats and decision-making effectiveness: An exploratory study" for the PhD degree at NHH.

The purpose of this thesis is to enhance the understanding of how data presentation formats may affect managerial decision processes.

Compared to previous studies in this area, Trond Vegard Johannessen has examined decision makers' need for data presentation formats in tasks that are more similar to real-life managerial tasks. He has focused not only on the outcome of a decision process, but also on how presentation formats may support decision makers' mental representation of the task and their decision process. In addition to studying the effects of either tables or graphs, he has included a combined presentation format. Furthermore, he has allowed the subjects to use decision aids, such as MS Excel.

In two experimental studies, Johannessen has explored how MBA students used graphs, tables and both presentation formats to solve two tasks varying in complexity and uncertainty. In his first study, he used verbal protocols to gain insights into how the subjects applied the presentation formats. In a second study, he also used eye tracking to complement the verbal-protocol data.

Johannessen found that decision makers need both presentation formats. Tables provided a basis for calculations to facilitate the integration of decision variables and result variables, which is important for effective decision making. Graphs provided an overview of the relationships among variables. Particularly XY graphs were important to enhance the decision makers' understanding of causal relationships among variables in the early phase of the decision process. Line graphs were primarily used to check whether the development of the result was as expected.

Johannessen's findings have implications for designers of information systems. Designers should include both tables and graphs in computerized systems to support managerial decision processes. Furthermore, data presented on the web or in enterprise systems should be easy to export to a spreadsheet format so that the data can be used for additional analyses.

Johannessen's research has also implications for managers. Managers using spreadsheets in their analyses should know how to programme formulas correctly, among others how to build dynamic models using relative cell references. This research has illustrated how poor spreadsheet skills may result in calculation errors that may seriously damage the outcomes of decision processes.

Prescribed topic for the trial lecture

"Effects of data presentation formats on managerial decision processes: Current trends and challenges. Task: Discuss what we know about the effects of data presentation formats on managerial decision processes. Identify gaps in our present knowledge, and discuss theoretical and methodological challenges of filling these gaps."

Time and place

Trial lecture: 10:15 in Karl Borch Aud., NHH
Defence: 12:15 in Karl Borch Aud., NHH

The trial lecture and thesis defense will be open to the public. Copies of the thesis will be available from:

Members of the evaluation committee
Professor Marcus Selart, NHH
Professor Shannon Rinaldo, Texas Tech University
Professor Øystein Sørebø, Buskerud and Vestfold University College

Supervising committee

Professor Anna Mette Fuglseth, principal supervisor, NHH
Professor emeritus Kjell Grønhaug, NHH