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Tag: case studies

Intuitions about case selection are often wrong

Imagine the following simple setup: there are two switches (X and Z) and a lamp (Y). Both switches and the lamp are ‘On’. You want to know what switch X does, but you have only one try to manipulate the switches. Which one would you choose to switch off: X, Z or it doesn’t matter? These are the results of the quick Twitter poll I did on the question: Two switches X and Z control lamp Z. Both switches & the lamp are On. You wanna learn what X does. You have one try. Which switch to press? — Dimiter Toshkov (@DToshkov) September 4, 2017 Clearly, almost half of the respondents think it doesn’t matter, switching X is the second choice, and only 2 out of 15 would switch Z to learn what X does. Yet, it is by pressing Z that we have the best chance of learning something about the effect of X. This seems quite counter-intuitive, so let me explain. First, let’s clarify the assumptions embedded in the setup: (A1) both switches and the lamp can be either ‘On’ [1 ] or ‘Off’ [0]; (A2) the lamp is controlled only by these switches; there is nothing outside the system that controls its output; (A3) X and Z can work individually or in combination (so that the lamp is ‘On’ only if both switches are ‘On’ simultaneously). Now let’s represent the information we have in a table: Switch X Switch Z Lamp Y 1 1 1 0 0 0 We are…

Unit of analysis vs. Unit of observation

Having graded another batch of 40 student research proposals, the distinction between ‘unit of analysis’ and ‘unit of observation’ proves to be, yet again, one of the trickiest for the students to master. After several years of experience, I think I have a good grasp of the difference between the two, but it obviously remains a challenge to explain it to students. King, Keohane and Verba (1994) [KKV] introduce the difference in the context of descriptive inference where it serves the argument that what often goes under the heading of a ‘case study’ often actually has many observations (p.52, see also 116-117). But, admittedly the book is somewhat unclear about the distinction and unambiguous definitions are not provided. In my understanding, the unit of analysis (a case) is at the level at which you pitch the conclusions. The unit of observation is at the level at which you collect the data. So, the unit of observation and the unit of analysis can be the same but they need not be. In the context of quantitative research, units of observation could be students and units of analysis classes, if classes are compared. Or students can be both the units of observation and analysis if students are compared. Or students can be the units of analyses and grades the unit of observations if several observations (grades) are available per student. So it all depends on the design. Simply put, the unit of observation is the row in the data table but the unit of analysis can…

Overview of the process and design of public administration research in Prezi

Here is the result of my attempt to use Prezi during the last presentation for the class on Research Design in Public Administration. I tried to use Prezi’s functionality to provide in a novel form the same main lessons I have been emphasizing during the six weeks (yes, it is a short course). Some of the staff is obviously an over-simplification but the purpose is to focus on the big picture and draw the various threads of the course together. Prezi seems fun but I have two small complaints: (1) the handheld device I use to change powerpoint slides from a distance doesn’t work with Prezi, and (2) I can’t find a way to make staff (dis)appear ala PowerPoint without zooming in and out .

Social science in the courtroom

Everyone who is interested in the sociology of science, causal inferences from observational data, employment gender discrimination, judicial sagas, or academic spats should read the latest issue of Sociological Methods & Research. The whole issue is devoted to the Wal-Mart Stores,Inc. v. Dukes et al. case – “the largest class-action employment discrimination suit in history”, with a focus on the uses of social science evidence in the courtroom.  The focal point of contestation is the report of Dr. Bielby – an expert for the plaintiff. In a nutshell, the report says that the gender bias in promotion decisions at Wal-Mart can be attributed to the lack of efforts to create a strong corporate culture and limit the discretion managers have in promotion decisions, which in turn allows for biased decisions. The evidence is mostly 1) a literature review that supports the causal links between corporate policies and corporate culture, corporate culture and individual behavior, discretion and biased individual behavior, and corporate policies and outcomes, and 2) description of the corporate policies and culture at Wal-Mart which points to a relatively weak policy towards gender discrimination and considerable discretion for managers in promotion decisions. Dr. Bielby describes the method as follows: “…look at distinctive features of the firm’s policies and practices and … evaluate them against what social scientific research shows to be factors that create and sustain bias and those that minimize bias” [the method is designated as “social framework analysis”]. What gives the case broader significance (apart from the fact that it directly concerns between half a million and a million and a half…