Measurement

Proposal

Second Draft Title Page Introduction Methods Section

Participants Materials Procedure

Appendix IRB Form Consent Form Debriefing Statement Study Materials

Measurement Measurement – the process of

assigning numbers to objects or events according to rules (Linn & Gronlund, 1995).

Psychological Measurement – concerned with evaluating individual differences in psychological constructs.

Levels of Measurement Nominal - Classifies objects into categories (e.g.,

gender)

Ordinal - Orders objects along a given dimension (e.g., rank order)

Interval - Measures “how much” of a variable is presentusing equal distances between scale points

May have a zero point that is arbitrary E.g., zero degrees Fahrenheit

Ratio - Has properties of all three previous scalesplus a true zero point

Evaluating the Quality of Measures

ReliabilityTest-retest Interrater Internal consistency

ValidityConcurrentDiscriminant

Types of Scales

Likert Most common

Has properties we need for data analysis Guttman Thurstone

Guttman Scale The purpose of Guttman scaling is to establish a one-

dimensional continuum for a concept you wish to measure. The scale is organized so that a respondent who agrees with

any specific question in the list will also agree with all previous questions.

INSTRUCTIONS: Place a check next to each statement you agree with.

_____ I would permit a child of mine to marry an immigrant.

_____ I believe that this country should allow more immigrants in.

_____ I would be comfortable if a new immigrant moved next door to me.

_____ I would be comfortable with new immigrants moving into my community.

_____ It would be fine with me if new immigrants moved onto my block.

_____ I would be comfortable if my child dated a new immigrant.

Thurstone Unidimensional scaling method You can give it to a participant and ask them to agree or disagree with each

statement. To get that person's total scale score, you average the scale scores of all the items that person agreed with.

Generate statements that describe specific attitudes that people might have towards persons with AIDS.

Statements are rated in terms of favorability in attitudes (e.g, 1-11). Statements are then selected for final scale based on ratings

Statements should reflect each level of rating

People with AIDS are like my parents (6) Because AIDS is preventable, we should focus our resources on prevention instead of curing (5) People with AIDS deserve what they got. (1) Aids affects us all (10) People with AIDS should be treated just like everybody else. (11) AIDS will never happen to me. (3) It's easy to get AIDS (5) AIDS doesn't have a preference, anyone can get it (9) AIDS is a disease that anyone can get if they are not careful (9) If you have AIDS, you can still lead a normal life (8) AIDS is good because it helps control the population. (2) I can't get AIDS if I'm in a monogamous relationship. (4)

Agree

Disagree

People with AIDS are like my parents.

Agree

Disagree

Because AIDS is preventable, we should focus our resources on prevention instead of curing.

Agree

Disagree

People with AIDS deserve what they got.

Agree

Disagree

Aids affects us all.

Agree

Disagree

People with AIDS should be treated just like everybody else.

Agree

Disagree

AIDS will never happen to me.

Agree

Disagree

It's easy to get AIDS.

Agree

Disagree

AIDS doesn't have a preference, anyone can get it.

Agree

Disagree

AIDS is a disease that anyone can get if they are not careful.

Agree

Disagree

If you have AIDS, you can still lead a normal life.

Agree

Disagree

AIDS is good because it helps control the population.

Agree

Disagree

I can't get AIDS if I'm in a monogamous relationship.

6

5

1

10

11

3

5

9

9

8

2

4

6+5+10+11+9+9+8+4=62

62/8 =7.75

Irritation Scale

Not at All

A Little Bit Moderately

Quite a Bit Extremely

irritated or annoyed? 1 2 3 4 5

furiously angry? 1 2 3 4 5

mad? 1 2 3 4 5

so angry you felt like hitting the assistant? 1 2 3 4 5

During the experiment, how much did the assistant make you feel the following:

Creating Scale Scores

Subject Condition Item 1 Item 2 Item 3 Item 4Mean Score

1 3 3 4 5 3 3.75

2 2 2 3 2 3 2.5

3 1 1 2 1 2 1.5

Subject Condition

Mean Irritation Score

1 3 3.75

2 2 2.5

3 1 1.5