Exam 10: Hypothesis Testing, Effect Size, and and Confidence Intervals: Two-Sample Designs

Identify the design of each experiment below as paired samples or independent samples. In each case give the df. -Ten students compared the legibility of headlines. In one condition the headlines were all in CAPITALS, in the other condition the first letters were capitalized. Each student judged on a scale of 1-10, first one headline, then the other.

The two kinds of t tests described in Chapter 10 were independent samples and paired samples.

A college teacher was assigned four freshmen advisees. He administered an attitude scale which measured liberalism-conservatism. Four years later, just before graduation, all four took the same scale again. High scores indicate conservative attitudes. The following scores were obtained. 2006 2010 26 15 22 23 17 14 15 10 Analyze them and write a conclusion.

As the value of p goes down, the value of d goes up.

Identify the design of each experiment below as paired samples or independent samples. In each case give the df. -A comparison of 54 fathers to their 54 sons all of whom were union members, showed the older men had higher spatial ability scores.

The 26 students who signed up for General Psychology reported their GPA. Each person was matched with another person on the basis of the GPAs, and two groups were formed. One group was taught with the traditional lecture method by Professor Nouveau. The other class could access the Web for the same lectures whenever they wished. At the end of the term, both classes took the same comprehensive final exam, and they also filled out a "satisfaction scale."Scores on both measures are shown below. Analyze the data and write a conclusion. Comprehensive Final Exam Lecture Group Web Group 50 56 72 75 64 62 82 90 89 91 65 65 74 72 85 87 80 76 65 79 82 77 75 78 64 70 Satisfaction Scale Lecture Group Web Group 25 31 18 19 40 38 31 35 17 24 22 20 14 18 36 35 27 31 22 27 23 27 28 28 20 23

The first 10 persons who arrived at a church service filled out a questionnaire on attitudes toward religion. The first 10 who arrived late for the service were spotted and, after the service, they filled out the same questionnaire. High scores indicate favorable attitudes. Find t and d for the data below and write a conclusion. On Time Late 10 11 13 7 7 11 4 10 8 8 5 14 9 13 11 12 7 10 6 14

An effect size index that is considered small is

The notion of generalizing from an experiment to a population was described by your text as the of an experiment.

A confidence interval about a mean difference gives a degree of confidence about the difference between two population means.

Null hypothesis statistical testing (NHST) allows an experimenter to conclude that the null hypothesis is

Identify each experiment below as an independent samples design or a paired samples design. -Fifth-grade American Indians were matched as a group to a group of New York Puerto Ricans on SES, IQ, and reading level. They were then given a questionnaire on attitudes toward school.

For a two-sample t test, an effect size that qualifies as large is

The actual amount of difference that exists between the two populations with unknown means (which you sample from) is the issue of

Identify for each description a) the independent variable, b) the dependent variable, and c) whether a paired or an independent-samples design is being described. -In an experiment sometimes referred to as the "intellectual blooming"experiment, the investigator randomly assigned students entering the fourth grade to the "intellectual bloomers"group or the control group. The results of a fictitious test were placed into all students' folders and for those designated bloomers, a statement that they were expected to show sharp gains during the year was included. At the end of the year, the mean achievement score for the two groups was compared.a) Independent variable _______________b) Dependent variable ______________c) Design ______________

The requirement that is built into the calculation of $s _ { X }$ , the requirement that costs one degree of freedom, is that

A one-tailed test of significance produced a t equal to -2.30, significant at the .05 level. The design of this experiment

A comparative psychologist was interested in the effect of X-irradiation on learning. A group of rats learned a simple maze and were paired on the basis of the number of errors. One group was X?irradiated; then both groups learned a new, more complicated maze, and errors were recorded. a. Test for a difference between the two groups. Find the effect size index. Write a conclusion for the study. X-irradiated Control 14 12 12 10 8 11 15 13 17 12 b. Identify the independent and dependent variables.

The t test was developed as a way to determine how well data fit the normal curve.

Data Set 10-2: The IQs of a group of special education students were compared to the IQs of their siblings who were not in special education. The following data were obtained. Special Ed Not Special Ed 70 104 65 99 67 95 -The study described in Data Set 10-2 is an example of