Exam 15: Repeated-Measures and Matched-Subjects Designs Interval Data

For questions below, use the following: A researcher predicts that training on the balance beam reduces reading errors among learning disabled youngsters. A random sample of 9 children was selected from the population of learning-disabled children from a large metropolitan school district. They were all given a reading test and their errors recorded. They were then trained on the balance beam for one year, and again their error scores on the reading test recorded. The data follows: Subject \# Before After 1 12 10 2 12 10 3 2 1 4 6 4 5 6 5 6 7 7 7 10 9 8 9 8 9 11 8 -For question 103, should Ho be rejected or accepted as a one-tail, And also should Ho be rejected as a two-tail? If rejected, state the alpha level.

In a paired t, when the correlation is significant,

For a given number of scores, the independent t has the degrees of freedom as the paired t.

Compared to the independent t, the paired t for a given sample size always

For the t test, other things being equal, the smaller the estimated standard error of difference, the greater the likelihood of

For the previous question , should Ho be rejected as a two-tail t? If rejected, state the alpha level.

Calculate a paired t on the following scores: Group 1 Group 2 10 6 4 4 12 9 5 3 4 3 6 5 8 7 7 4

For the previous question, should Ho be rejected as a one-tail t? If rejected, state the alpha level.

Sampling error is assumed

With an equal mean difference, when the correlation is significant, the paired t results in a higher t ratio than does the independent t.

The within-subjects ANOVA may never result in a negative value.

For the previous question, should Ho be rejected as a two-tail t? If rejected, state the alpha level.

Of the following research designs, the one(s) in which the sample scores must be independent of each other, is (are) the

An F ratio may never be used on data from a matched-subjects design.

With interval data and random assignment of subjects, the appropriate analysis of data from an between subjects (two group) design would be

When subjects are measured in the "pre" condition, then the independent variable is inserted, and the subjects are measured again in the "post" condition, the experimental design is

Whenever the repeated-measures design is used

With a paired t, the greater the number of paired scores, the greater the number of degrees of freedom.

Using the data from question 85, calculate an independent t.

For questions below use the following: A researcher suspects that increasing illumination increases motoric speed. A group of 7 subjects was randomly selected and tested on the Digit Symbol subtest of the WAIS-R IQ test. The same subjects were tested under three illumination conditions, low light, medium light and high light. Their scores under each condition were as follows: Subject \# Low Light Medium Light High Light 1 7 10 11 2 8 7 10 3 6 8 10 4 5 6 9 5 4 4 7 6 3 5 6 7 8 10 13 -Calculate the appropriate F ratio.