## PSYC 815 Quiz Basic Statistics

**PSYC 815 Quiz: Basic Statistics and Research Design **

Covers the Textbook material from Module 1: Week 1.

- An alternative hypothesis must include the anticipated direction of variance.
- An
*a priori*power analysis is important for which of the following reasons… - A researcher wants to determine if the sample mean score of a group of 40 children is significantly higher or lower than the mean of a standardized test of reading when both the population mean and standard deviation are known.
- A researcher wants to determine if Republicans and Democrats differ in their attitudes about the war in Iraq. He identifies a set of 7 Republican students and matches each student with a Democrat on the basis of age, family income and race. The researcher then asks each student to complete a questionnaire, where higher scores represent a “pro-war” attitude. What is the appropriate test for this data?
- When a researcher wants to determine if the dependent measure scores of a sample of participants significantly increases from pretest to posttest, what statistic would he use?
- Degree to which a scale informs you of the construct being measured is called__________; Discrepancy between what we’re measuring and the actual value of what we are measuring.
- If a researcher wants to determine if one sample mean significantly differs from a population mean and she uses the standard deviation of the sample to estimate the standard deviation of the population, what statistic would she use?
- “Any measurable characteristic of a population” defines which one of the following terms.
- A researcher predicts that practice improves children’ s accuracy on a fine motor skills game (high score indicates high accuracy). He tests the children before and after 15 minutes of practice. What is the appropriate analysis of the following data?
- What is the independent variable in this research problem?
- What is the dependent variable in this research problem?
- Is there a significant difference in group means on the BDI scores across the two groups using an alpha level of .05?
- A good hypothesis should predict the following:
- If a researcher rejects the null hypothesis and in actual truth the null is true which one of the following is the best answer?
- If you were most concerned about avoiding making a Type I error you would choose an α = .10?
- In addition to stating the results of the hypothesis tested, it is also important to report other information. Which one of the following choices is the best answer?
- The alternative hypothesis is the hypothesis that is tested statistically.
- The hypothesis testing process is the most widely used statistical tool in scientific research.
- The variables stated in an alternative hypothesis reflect the changes in an outcome (dependent variable) that can be attributed to a cause (independent variable).
- Using an alpha criterion of α = .01, which symbolic statement below indicates that we failed to reject the null hypothesis at the .01 level of significance?
- Researchers tested the null hypothesis related to the above stated alternative hypothesis by comparing the means of student achievement across the two chemistry curriculum conditions. The significant probability finding was
*p*= .006 related to the difference between means and the alpha criterion is α = .05. Is it correct to say, we conclude that there is a significant difference in student chemistry achievement means among high school chemistry students across the two chemistry curriculum

conditions,*p*< .05? - Which one of the following represents the way to state the narrative alternative hypothesis symbolically? The μ1 refers to the population mean that is being estimated on science achievement of the students in the condition of the standard chemistry curriculum that is augmented with intelligent computer-based chemistry tutors and μ2 refers to the population mean that is being estimated on science achievement of the students in the condition of the standard chemistry curriculum only.
- Which one of the following items best describes the independent variable in the alternative hypothesis stated above?
- What one of the following items best describes the dependent variable in the alternative hypothesis stated above?
- Which term below best describes the stated alternative hypothesis?