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Unformatted text preview: Chapter 1 Solutions 1-2 A sample is a set of observations drawn from the population of interest that, it is hoped, share the same characteristics as the population of interest. A population includes all possible observations about which weˆ ad like to know something. 1-4 Statisticians use scale as another term for an interval measure. They also use scale as a word for many measurement tools, particularly those that involve a series of items that test-takers must complete. 1-6 An independent variable is a variable that we either manipulate or observe to determine its effects on the dependent variable; a dependent variable is the outcome variable that we hypothesize to be related to, or caused by, changes in the independent variable. 1-8 Reliability refers to the consistency of a measure. Validity refers to the extent to which a test actually measures what it was intended to measure. A measure that is valid absolutely must be reliable, but a reliable measure is not necessarily a valid one. 1-10 In everyday language, people often use the word experiment to refer to something they are trying out to see what will happen. Researchers use the term to refer to a type of study in which participants are randomly assigned to levels of the independent variable. 1-12 In a between-groups research design, participants experience one, and only one, level of the independent variable. In a within-groups research design, all levels of the independent variable are experienced by all participants in the study. 1-14 a. 130 people b. All people living in urban areas in the United States 1-16 Descriptive statistic 1-18 a. Answers may vary, but one way is to sort people into groups such as ”long distance”, ”medium distance”, and ”short distance walked”. b. Answers may vary, but pedometers could be used to measure steps taken and miles walked, both of which are scale measures. 1-20 Answers may vary, but on a national level, one could look at the rate of houses in foreclosure or the amount of government debt. 1-22 There are two levels of physical distance (within 100 miles and 100 miles or farther) and three levels of emotional distance (knowing no one who was affected, knowing people who were affected but lived, and knowing someone who died). 1-24 a. Skin tone b. Severity of facial wrinkles c. Three levels (light, medium, and dark) 1-26 a. The sample is the 60,000 people they studied....
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This note was uploaded on 12/05/2011 for the course PSYCH 100A taught by Professor Marken during the Summer '07 term at UCLA.
- Summer '07