Chap 1 Data

Question 1

Chi-squared distributions:

Answer 1

A family of distributions associated with the chi-squared statistic (X2)

Question 2

Constant

Answer 2

A construct that has only one value.

e.g. if every member of a sample was 10 years old, the “age” construct would be constant.

Question 3

Convenience Sampling

Answer 3

Selecting a sample based on ease of access or availability

Question 4

Correlational research design

Answer 4

A style of research used to examine the associations among variables. Variables are not manipulated by the researcher in this type of research design.

Question 5

Dependent Variable

Answer 5

The values of the dependent variable are hypothesized to depend on the values of the independent variable.
e.g. height depends in part on gender.

Question 6

Descriptive Statistics

Answer 6

Statistics used to describe the characteristics of a distribution of scores.

Question 7

Dichotomous Variable

Answer 7

A value that has only two discrete values.

e.g. a pregnancy variable can have a value of 0 for “ not pregnant” and 1 for “pregnant”

Question 8

Distribution

Answer 8

Any collection of scores on a variable

Question 9

Experimental research design

Answer 9

A type of research in which the experimenter, or researcher, manipulates certain aspects of the research. These usually include manipulations of the independent variable and assignment of cases to groups.

Question 10

Frequency

Answer 10

How often a score occurs in a distribution

Question 11

Generalize (or Generalizability)

Answer 11

The ability to use the results of the data collected from a sample to reach conclusions about the characteristics of the population, or any other cases not included in the sample.

Question 12

Independent Variable

Answer 12

A variable on which the values of the dependent variable are hypothesized to depend. Independent variables are often, but not always, manipulated by the researcher.

Question 13

Inferential Statistics

Answer 13

Stats derived from a sample data, that are used to make inferences about the population from which the sample was drawn.

Question 14

Interval or Ratio Variable

Answer 14

Variables measured with numerical values with equal distance, or space b/w each number.
e.g. 2 is twice as much as 1, 4 is twice as much as 2, the distance b/w 1 and 2 is the same as the distance b/w 2 and 3.

Question 15

Mean

Answer 15

The arithmetic average of a distribution of scores

Question 16

Nominally scaled variable

Answer 16

A variable in which the numerical values assigned to each category are simply labels rather than meaning numbers.

Question 17

Normal Distribution

Answer 17

A bell-shaped frequency distribution of scores that has a mean, median, and mode in the middle of the distribution and is symmetrical and asymptotic.

Question 18

Ordinal Variable

Answer 18

Variables measured with numerical values where the numbers are meaningful (e.g. 2 is larger than 1) but the distance b/w the numbers is not constant.

Question 19

Parameter

Answer 19

A value, or values derived from a population data

Question 20

Population

Answer 20

The collection of cases that comprise the entire set of cases with the specified characteristics.
e.g. all living adult males in the United States.

Question 21

Qualitative (or categorical) Variable

Answer 21

A variable that has discrete categories. if the categories are given numerical values, the values have meaning a nominal reference but not as numerical values.
e.g. in 1 = “male” and 2=”female”, 1 is not more or less than 2

Question 22

Quantitative ( or continous) Variable

Answer 22

A variable that has assigned values and the values are ordered and meaningful, such that 1 is less than 2, 2 is less than 3, and so on.

Question 23

Random assignment

Answer 23

Assignment members of a sample to different groups

(e.g. experimental and control) randomly, of without consideration of any of the characteristics of sample members.

Question 24

Random Sample ( or random sampling)

Answer 24

Selecting cases from a population in a manner that ensures each member of a population has a equal chance of being selected into the sample.

Question 25

Representative Sampling

Answer 25

A method in selecting a sample in which members are purposely selected to create a sample that represents the population on some characteristic(s) of interest.
eg. when a sample is selected to have the same percentages of various ethnic groups as the larger population).

Question 26

Sample

Answer 26

A collection of cases from a larger population

Question 27

Statistic

Answer 27

A characteristic, or value derived from a sample data

Question 28

t distribtuions

Answer 28

A family of distributions associated with the t statistic, commonly used in the comparison of sample means and tests of statistical significance for correlation coefficients and regression slopes.

Question 29

Variable

Answer 29

Any construct with more than one value that is examined in research.