The Wary Student, Part 8: Interaction-Effect Results

Because the negative cooperation p value missed .01 (.033) significance because of the Bonferroni correction, an analysis of covariance (ANCOVA) was attempted in order to increase the power of the statistical tests. The ANCOVA analysis attempts to use a second variable (called a “covariate” or CV) to explain some of the sample variation in the dependent variable (DV), which increases the observed power of the independent variable (IV). In order to run an ANCOVA, two assumptions must be made: first the CV is correlated with the DV but not the DV, and that the DV and and the IV do not interact. This second requirement called the homogeneity of regression, is similar to the homogeneity of variance test used in the ANOVA

Only one of the assumptions for ANCOVA was met. A perason’s correlation showed that the test for neutral cooperation was positively correlated with negative cooperation (F = .298, p < .01) but not correlated with cognitive load (F = .004, p = .955). Then, to test the homogeneity of regression assumption a two-way ANOVA was run with both the IV and the CV as independent variables. The results failed to allow an ANCOVA, but are fascinating in their own right.

Raw visualization of the interaction effect.
Cognitive load decreases the negative cooperation of those who were neutrally cooperative

Specifically, the two-way ANOVA results (F = 22.257, p = .0000048, η2 = .112) show a strong interaction effect. That is, cognitive load strongly effects the negative cooperative behavior of those who are neutrally cooperative. In this two-factor ANOVA, both cognitive load (F = 25.144, p = 0.0000013) and neutral cooperation (F = 15.171, p = 0.00014) were significant. Tukey post-hoc tests were not run because both condition and neutral cooperation had only two levels. Among those who accepted the unfair allocate resources, increased cognitive load barely altered the degree of negative cooperation (decreasing it from an average of .09 to .07 points). However, among those who rejected the unfair division, higher cognitive load reduced negative cooperation (from n = 21, μ = .8571, to n = 20, μ = 0).

The Wary Student, a tdaxp research project
1. Abstract
2. Cognitive Load
3. Cooperative Behavior
4. Method
5. The Experiments
6. Hypotheses
7. Main-Effect Results
8. Interaction-Effect Results
9. Discussion
10. Future Research
11. Bibliography

Republican Netroots Help Democrats

Hernandez, R. 2007. Hispanic voters enjoy new clout with Democrats. New York Times. 10 June 2007. Available online:

When I started this blog, grassroot suicidal foolishness of this scale was typically reserved for the lunatics at Daily Kos.

Helped by the fight over immigration, Democrats seeking their party’s presidential nomination are moving to court Hispanic voters like never before, as a string of early primary states with sizable Hispanic voting blocs prompt candidates to hire outreach consultants, start Spanish-language Web sites and campaign vigorously before Hispanic audiences.

The battle for Hispanic voters is a result of the decision by several states with large Hispanic populations to move their presidential primaries to early 2008, including California, Florida and New York. Roughly two-thirds of the nation’s Hispanic residents live in nine of the states that will hold Democratic primaries or caucuses on or before Feb. 5.

Strategists say the influence of Hispanic voters is likely to be amplified next year because of an unusually intense response in many Hispanic communities to immigration policy. Conservative Republicans, with the help of some left-leaning Democrats, teamed up to derail an immigration bill in the Senate on Thursday that would have provided a path to citizenship for illegal immigrants.

Contempt for latin Americans was once most visible on the left, too.

Know-Nothings, but Patriotic Know-Nothings

The celebration of much of the Republican blogosphere about the defeat of the immigration bill is saddening. The party that did so much to pass NAFTA is degenerating, at least in its public face, into conservativism-as-a-reflex. It’s easy to say that the Republican netroots are intellectually empty, and it’s hard to disagree.

There are real reasons to oppose the immigration bill, but these rarely come up. Instead, mindless mantras of “Enforcement First!” come from bloggers who somehow don’t apply the same policy to other areas of the law. (Should all gun sales stop until all illegal guns are off the street? Should all stock trading stop until all corporate crooks are behind bars?)

Oh well. Remember when I said this:

At this point, I do not care if decapitated boyscouts are found in the offices of the Republican Congressional Leadership. The GOP must win back the House and the Senate in ’08.

It’s still true.

I’ll vote Republican even if my party stays the party of the know-nothings, because the Democratic Party is even worse. Stupid is better than defeatist any day.

Colomarine blog

I’m getting a lot of trackback spam with the title “Colomarine post,” apparently uniquely identified to make it easier to see where it worked. The Blog name in each if “Colomarine blog,” and the content is always “all about Colomarine and top news.” The IP address is, though strangely the Blog URL reads “”

So what is colomarine? When I search for “Colomarine -blog” I get only 44 results, and they all seem to be to a family name.