Research Methods for the Behavioral Sciences
5th Edition
ISBN: 9780357231913
Author: Frederick J Gravetter; Lori-Ann B. Forzano
Publisher: Cengage Limited
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 10, Problem 9E
Explain how the pretest helps minimize the threat to internal validity from individual differences in a pretest posttest nonequivalent control group design.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
The average miles per gallon for a sample of 40 cars of model SX last year was 32.1, with a population standard deviation of 3.8. A sample of 40 cars from this year’s model SX has an average of 35.2 mpg, with a population standard deviation of 5.4.
Find a 99 percent confidence interval for the difference in average mpg for this car brand (this year’s model minus last year’s).Find a 99 percent confidence interval for the difference in average mpg for last year’s model minus this year’s. What does the negative difference mean?
A special interest group reports a tiny margin of error (plus or minus 0.04 percent) for its online survey based on 50,000 responses. Is the margin of error legitimate? (Assume that the group’s math is correct.)
Suppose that 73 percent of a sample of 1,000 U.S. college students drive a used car as opposed to a new car or no car at all.
Find an 80 percent confidence interval for the percentage of all U.S. college students who drive a used car.What sample size would cut this margin of error in half?
Chapter 10 Solutions
Research Methods for the Behavioral Sciences
Ch. 10.1 - Define, compare, and contrast the experimental,...Ch. 10.2 - Define a nonequivalent group design and identify...Ch. 10.2 - Explain how individual differences threaten the...Ch. 10.2 - Describe the two nonexperimental nonequivalent...Ch. 10.2 - Explain how a simple modification of the...Ch. 10.3 - Define a pre-post design and identify examples of...Ch. 10.3 - Identify the threats to internal validity for...Ch. 10.3 - Describe the nonexpenmental pretest-posttest...Ch. 10.3 - Explain how replacing the single observation...Ch. 10.4 - Define cross-sectional and longitudinal designs,...
Ch. 10.5 - Identify the statistical techniques that are...Ch. 10.5 - Explain how the terms quasi-independent variable...Ch. 10 - In addition to the key words, you should also be...Ch. 10 - Why are studies that examine the effects of aging...Ch. 10 - Explain why we can be more confident about causal...Ch. 10 - Give an example of a situation (aside from gender)...Ch. 10 - In this chapter, we described a study in which...Ch. 10 - Mueller and Oppenheimer (2014) conducted a series...Ch. 10 - A researcher measures personality characteristics...Ch. 10 - A researcher wants to describe the effectiveness...Ch. 10 - Explain how the pretest helps minimize the threat...Ch. 10 - Describe the basic characteristics of a pre-post...Ch. 10 - To evaluate the effectiveness of a new television...Ch. 10 - Prob. 12ECh. 10 - A researcher wants to describe how fine motor...Ch. 10 - Identify the appropriate statistical test for each...Ch. 10 - The college offers all students an optional...Ch. 10 - All of us have a tendency to categorize people...Ch. 10 - Prob. 2EACh. 10 - Prob. 3EA
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- You want to compare the average number of tines on the antlers of male deer in two nearby metro parks. A sample of 30 deer from the first park shows an average of 5 tines with a population standard deviation of 3. A sample of 35 deer from the second park shows an average of 6 tines with a population standard deviation of 3.2. Find a 95 percent confidence interval for the difference in average number of tines for all male deer in the two metro parks (second park minus first park).Do the parks’ deer populations differ in average size of deer antlers?arrow_forwardSuppose that you want to increase the confidence level of a particular confidence interval from 80 percent to 95 percent without changing the width of the confidence interval. Can you do it?arrow_forwardA random sample of 1,117 U.S. college students finds that 729 go home at least once each term. Find a 98 percent confidence interval for the proportion of all U.S. college students who go home at least once each term.arrow_forward
- Suppose that you make two confidence intervals with the same data set — one with a 95 percent confidence level and the other with a 99.7 percent confidence level. Which interval is wider?Is a wide confidence interval a good thing?arrow_forwardIs it true that a 95 percent confidence interval means you’re 95 percent confident that the sample statistic is in the interval?arrow_forwardTines can range from 2 to upwards of 50 or more on a male deer. You want to estimate the average number of tines on the antlers of male deer in a nearby metro park. A sample of 30 deer has an average of 5 tines, with a population standard deviation of 3. Find a 95 percent confidence interval for the average number of tines for all male deer in this metro park.Find a 98 percent confidence interval for the average number of tines for all male deer in this metro park.arrow_forward
- Based on a sample of 100 participants, the average weight loss the first month under a new (competing) weight-loss plan is 11.4 pounds with a population standard deviation of 5.1 pounds. The average weight loss for the first month for 100 people on the old (standard) weight-loss plan is 12.8 pounds, with population standard deviation of 4.8 pounds. Find a 90 percent confidence interval for the difference in weight loss for the two plans( old minus new) Whats the margin of error for your calculated confidence interval?arrow_forwardA 95 percent confidence interval for the average miles per gallon for all cars of a certain type is 32.1, plus or minus 1.8. The interval is based on a sample of 40 randomly selected cars. What units represent the margin of error?Suppose that you want to decrease the margin of error, but you want to keep 95 percent confidence. What should you do?arrow_forward3. (i) Below is the R code for performing a X2 test on a 2×3 matrix of categorical variables called TestMatrix: chisq.test(Test Matrix) (a) Assuming we have a significant result for this procedure, provide the R code (including any required packages) for an appropriate post hoc test. (b) If we were to apply this technique to a 2 × 2 case, how would we adapt the code in order to perform the correct test? (ii) What procedure can we use if we want to test for association when we have ordinal variables? What code do we use in R to do this? What package does this command belong to? (iii) The following code contains the initial steps for a scenario where we are looking to investigate the relationship between age and whether someone owns a car by using frequencies. There are two issues with the code - please state these. Row3<-c(75,15) Row4<-c(50,-10) MortgageMatrix<-matrix(c(Row1, Row4), byrow=T, nrow=2, MortgageMatrix dimnames=list(c("Yes", "No"), c("40 or older","<40")))…arrow_forward
- Describe the situation in which Fisher’s exact test would be used?(ii) When do we use Yates’ continuity correction (with respect to contingencytables)?[2 Marks] 2. Investigate, checking the relevant assumptions, whether there is an associationbetween age group and home ownership based on the sample dataset for atown below:Home Owner: Yes NoUnder 40 39 12140 and over 181 59Calculate and evaluate the effect size.arrow_forwardNot use ai pleasearrow_forwardNeed help with the following statistic problems.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
College Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Statistics 4.1 Introduction to Inferential Statistics; Author: Dr. Jack L. Jackson II;https://www.youtube.com/watch?v=QLo4TEvBvK4;License: Standard YouTube License, CC-BY