Identifying Variables - Answers
You were asked to read the following study
and do the following:
1. Identify the purpose of this study.
2. List all variables included in the study.
3. Identify which variables are independent and dependent.
Answers
1. Identify the purpose of this study.
The purpose was to learn whether any differences exist in several classroom behaviors (several DVs) between poor and strong readers.
2. List all variables included in the study.
I counted at least 9 variables. These were identified in various sections of the report.
In the “Subjects” section (p. 162) the authors explain these two variables:
V1. Grade level (1, 3, 5, 7, 9, and 11)
V2. Reading level of sampled students (good vs. poor as defined by standardized
testing performance)
Normally authors report how variables were measured in the Instrumentation or Materials section, but in this study the authors explain how they measure the 7 behaviors in the “Procedures” section:
V3. Seconds to start (an assigned task)
V4. Materials missing (from student’s work area)
V5. Noise (distracting sounds by student)
V6. Out of place (student movement beyond their work area)
V7. Physical contact or destruction (inappropriate contact)
V8. Off task (behaviors not represented by noise, out of place, or physical
contact)
V9. Volunteering (attempt to give answers/information)
Another excellent location to identify variables are tables of results reported in the “Results” section of a report. For example, look at Table 1 on page 164 and determine the number of variables listed in Table 1. How many do you see?
Note there are 8 variables presented in Table 1, the 7 behaviors and reading level. How many variables are presented in Table 2?
There are 8 variables presented in Table 2, the 7 behaviors and grade level.
3. Which of the variables identified are independent and dependent?
It seems the authors first measured grade level and student reading level, then began observing the 7 behaviors. So based upon the sequence, and the logic used, grade level and reading level are the IVs, and the 7 behaviors are the DVs. In addition the authors’ analyses of these data treat reading level as the IV and the 7 behaviors as the DVs.
As a side note, it is possible to argue that the theoretical order here is a bit confused, however, that was not addressed in this study. For example, wouldn’t off-task behaviors influence reading performance? If yes, which is the IV and DV --- it is not altogether clear in this study which is IV and which is DV.