Chapter One Flashcards
What is a Descriptive Statistic?
A descriptive statistic organizes, summarizes, and
communicates a group of numerical observations.
What is an Inferential Statistic?
An inferential statistic uses sample data to make general
estimates about the larger population.
What is a Sample?
A sample is a set of observations drawn from the
population of interest.
What is a population?
The population includes all possible observations about
which we’d like to know something.
What is the difference between Descriptive Statistics and Inferential Statistics?
Descriptive Statistics summarize numerical information about a sample.
Inferential Statistics draw conclusions about the broader population based on numerical information from a sample.
What is a Variable?
A variable is any observation of a physical, attitudinal, or behavioral characteristic that can take on different values.
What is a Discrete Observation?
A discrete observation can take on only specific values (e.g., whole numbers); no other values can exist between these numbers.
What is a Continuous Observation?
A continuous observation can take on a full range of values (e.g., numbers out to several decimal places); an infinite number of potential values exists.
What is a nominal variable?
A nominal variable is a variable used for observations that have categories, or names, as their values.
What is an ordinal variable?
An ordinal variable is a variable used for observations that have rankings (i.e., 1st, 2nd, 3rd . . .) as their values.
What is an Interval Variable?
An Interval Variable is a variable used for observations that have numbers as their values; the distance (or interval) between pairs of consecutive numbers is assumed to be equal.
What is a Ratio Variable?
A Ratio Variable is a variable that meets the criterion for an interval variable but also has a meaningful zero point.
What are the three main types of Variables?
The three main types of variables are nominal (or categorical), ordinal (or ranked), and scale. The third type A scale variable is a variable that meets the criteria for an interval variable or a ratio variable
What is a Scale Variable?
A Scale Variable is a variable that meets the criteria for an interval variable or a ratio variable.
What is a Level?
A Level is a discrete value or condition that a variable can take on.
What is an Independent Variable?
An Independent Variable has at least two levels that we either manipulate or observe to determine its effects on the Dependent Variable.
What is a Dependent Variable?
A dependent variable is the outcome variable that we hypothesize to be related to or caused by changes in the independent variable.
What is a Confounding Variable?
A Confounding Variable is any variable that systematically varies with the independent variable so that we cannot logically determine which variable is at work; also called a Confound
Why do we conduct Research?
We conduct research to see if the independent variable predicts the dependent variable.
What does Reliability refer to?
Reliability refers to the consistency of a measure.
What does Validity refer to?
Validity refers to the extent to which a test actually measures what it was intended to measure.
What are the properties of a Good Measure?
A Good Measure is both Reliable and Valid.
What is Hypothesis Testing?
Hypothesis Testing is the process of drawing conclusions about whether a particular relation between variables is supported by the evidence.
What is operationalize or an operational definition?
An operational definition specifies the operations or procedures used to measure or manipulate a variable.
What is a Correlation
A correlation is an association between two or more variables.
How does Random Assignment work?
In random assignment every participant in a study has an equal chance of being assigned to any of the groups, or experimental conditions, in the study.
What is an Experiment?
An experiment is a study in which participants are randomly assigned to a condition or level of one or more independent variables.
What is the difference between a Correlational Study and an Experiment?
When possible, researchers prefer to use an experiment rather than a correlational study. Experiments use random assignment, which is the only way to determine whether one variable causes another.
How does a Between-Groups research design work?
In a between-groups research design, participants experience one and only one level of the independent variable.
How does a Within-Groups research design work?
In a within-groups research design all participants in the study experience the different levels of the independent variable; also called a repeated-measures design.
What is an outlier?
An outlier is an extreme score that is either very high or very low in comparison with the rest of the scores in the sample.
What is outlier analysis?
In outlier analysis, studies examine observations that do not fit the overall pattern of the data in an effort to understand the factors that influence the dependent variable.
