# case0402: Cognitive Load In Sleuth3: Data Sets from Ramsey and Schafer's "Statistical Sleuth (3rd Ed)"

## Description

Educational researchers randomly assigned 28 ninth-year students in Australia to receive coordinate geometry training in one of two ways: a conventional way and a modified way. After the training, the students were asked to solve a coordinate geometry problem. The time to complete the problem was recorded, but five students in the “conventional” group did not complete the solution in the five minute alloted time.

## Usage

 `1` ```case0402 ```

## Format

A data frame with 28 observations on the following 3 variables.

Time

the time (in seconds) that the student worked on the problem

Treatment

factor variable with two levels—`"Modified"` and `"Conventional"`

Censored

1 if the individual did not complete the problem in 5 minutes, 0 if they did

## Source

Ramsey, F.L. and Schafer, D.W. (2013). The Statistical Sleuth: A Course in Methods of Data Analysis (3rd ed), Cengage Learning.

## References

Sweller, J., Chandler, P., Tierney, P. and Cooper, M. (1990). Cognitive Load as a Factor in the Structuring of Technical Material, Journal of Experimental Psychology General 119(2): 176–192.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25``` ```str(case0402) # level 1 of Treatment is "Conventional" (1st alphabetically) attach(case0402) boxplot(Time ~ Treatment) median(Time[Treatment=="Conventional"])-median(Time[Treatment=="Modified"]) wilcox.test(Time ~ Treatment, exact=FALSE, correct=TRUE, alternative="greater") # Rank-sum test; alternative: group 1 is greater wilcox.test(Time ~ Treatment, exact=FALSE, correct=TRUE, alternative="two.sided", conf.int=TRUE) # Use 2-sided to get confidence int. ## DOT PLOTS FOR PRESENTATION xTreatment <- ifelse(Treatment=="Conventional",1,2) # Make numerical values myPointCode <- ifelse(Censored==0,21,24) plot(Time ~ jitter(xTreatment,.2), # Jitter the 1's and 2's for visibility ylab="Completion Time (Sec.)", xlab="Training Method (jittered)", main="Test Completion Times from Cognitive Load Experiment", axes=FALSE, pch=myPointCode, bg="green", cex=2, xlim=c(.5,2.5) ) axis(2) # Draw y-axis as usual axis(1, tick=FALSE, at=c(1,2), # Draw x-axis without ticks labels=c("Conventional (n=14 Students)","Modified (n=14 Students)") ) legend(1.5,300, legend=c("Did not Complete in 300 sec","Completed in 300 sec."), pch=c(24,21), pt.cex=2, pt.bg="green") detach(case0402) ```

Sleuth3 documentation built on May 29, 2017, 11:28 a.m.