Unit of Analysis

1
Unit of Analysis

• Kristy Marynak
• POL-221
• 27 January 2003

2
Introduction

• Purpose of Presentation
• To define and begin to specify the unit of
  analysis of a hypothesis.

3
What Is a Unit of Analysis?

• Definition In a research project, the unit of
  analysis is the particular type of actor whose
  political behavior is named in a hypothesis.
• Could be individuals
• groups
• artifacts
• geographical units
• social interactions

4
Example 1

• Sample Hypothesis
• Math majors at Davidson are more likely to have
  calculators, while English majors are more likely
  to have dictionaries.
• Unit of Analysis
• The Davidson student.

5
Example 2

• Sample Hypothesis
• Republican Senate members are more likely to vote
  for legislation desired by Bush than Democratic
  senate members.
• Unit of Analysis
• The individual member of the Senate.

6
Important Considerations for Evaluating Unit of
Analysis

• Independence of Observations
• Level of Generalization
• Ecological Fallacy
• Consistency of Unit of Analysis

7
Consideration 1 Independence of Observation

• For an experiment to be scientific, it must be
  replicable. Thus, there must be independence of
  observations and units.
• We must assess whether observations are
  independent, especially when groups of
  observations are linked to one another. This
  gets complicated.

8
Consideration 2 Level of Generalization

• Example A researcher measures 10 children in 10
  classrooms from 10 different schools.
• Three possible levels of generalizations
• The student, the classroom, the school.
• Tendency We want to draw conclusions about
  persons, so we identify the person as the unit of
  analysis.
• Problem Ecological Fallacy.
• The conclusions drawn from an analysis conducted
  at a group level may not apply at the individual
  level, or vice versa.

9
Example of Ecological Fallacy

• Sample Observation A study shows that counties
  with high rates of driving under the influence
  also have high proportions of conservative
  Republicans.
• Hypothesis Conservative Republicans drive under
  the influence more than non-Republicans.
• Fallacy There is no relationship between
  Republicans and drunk drivers.

10
Consideration 3 Consistency of Unit of Analysis

• A common mistake is to mix different units of
  analysis in the same hypothesis.
• Example The more healthy a person is, the more
  socialist his country is.

11
REVIEW
Unit of Analysis The major entity that you are
analyzing in your study.

• Important Considerations
• - Independence of Observations
• - Level of Generalizations
• - Consistency of Unit of Analysis

12
Works Consulted

• Johnson, Janet Buttolph, et al. Political
  Science Research Methods. 60-63.
• Kenny, David. Choice of Unit of Analysis.
  users.rcn.com
• Trochim, William M.K. Unit of Analysis.
  trochim.human.cornell.edu