Delaware Chapter, ASA

Dinner Meeting: May 2003

Speakers: Ratna Nandakumar, Ph.D.
School of Education
University of Delaware

Larry Hotchkiss IT User Services
University of Delaware
(Notes online.)


Factor Analysis and Item Response Theory for Attitudinal Data


Many surveys contain a sequence of items each stating an opinon, attitude, or other subjective idea. For example --

Granny Smith apples taste good (circle 1).
Disagree Agree Strongly

Respondents are asked to indicate their degree of agreement or disagreement with each statement. Sequential integers are assigned to the response options.

Generally, all items in a set are designed to measure one underlying latent trait such as attitude on abortion, or opinion about the political system. This appears to imply that a factor analysis of item responses will produce one factor. However, linear factor analysis of such data often produces two factors instead of one. Why?

This presentation summarizes and extends recent research which proposes an interesting answer to this question. The presentation describes Item Response Theory as an alternative to the factor-analysis model for representing attitudinal survey items and gives several real-data examples of its use.

Date: Thursday, May 15, 2003

Social hour -- 6:00 pm
Dinner -- 6:30 pm
Speaker -- 7:15 pm

Newark Holiday Inn
Oliver's Restaurant map

Soup: Vegetable soup
Salad: Caesar salad
Entree: Slow Roasted Prime Rib au Jus
Dessert: Cake

$25 for members, $10 for students



Lidia Rejto by Monday, May 12, 2003.
Phone: 302-831-8034
Fax: 302-831-6243
Email: Lidia Rejto.

If you desire a vegetarian meal, please so indicate in your RSVP.

Please note: Be sure to RSVP by this date, to assure a meal is reserved for you.

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