Flashcards in 2.2 Psychologists Use Descriptive, Correlational, and Experimental Research Designs to Understand Behavior Deck (23):

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## research design

### the specific method a researcher uses to collect, analyze, and interpret data

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## Descriptive research

### research designed to provide a snapshot of the current state of affairs

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## Correlational research

### research designed to discover relationships among variables and to allow the prediction of future events from present knowledge

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## Experimental research

### research in which initial equivalence among research participants in more than one group is created, followed by a manipulation of a given experience for these groups and a measurement of the influence of the manipulation

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## case studies

### descriptive records of one or more individual’s experiences and behavior

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## survey

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- a measure administered through either an interview or a written questionnaire to get a picture of the beliefs or behaviors of a sample of people of interest.

- The people chosen to participate in the research (known as the sample) are selected to be representative of all the people that the researcher wishes to know about (the population).

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## naturalistic observation

### research based on the observation of everyday events

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## descriptive statistics

### numbers that summarize the distribution of scores on a measured variable

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## normal distribution

### A data distribution that is shaped like a bell

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## central tendency

### the point in the distribution around which the data are centered

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## dispersion

### spread

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## arithmetic mean

### the most commonly used measure of central tendency

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## median

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- used as an alternative measure of central tendency when distributions are not symmetrical.

- the score in the center of the distribution, meaning that 50% of the scores are greater than the median and 50% of the scores are less than the median

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## mode

### represents the value that occurs most frequently in the distribution

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## range

### of the variable is the maximum observed score minus the minimum observed score

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## standard deviation

### symbolized as s, is the most commonly used measure of dispersion

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## scatter plot

### a visual image of the relationship between two variables

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## Pearson correlation coefficient

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- The most common statistical measure of the strength of linear relationships among variables

- value: ranges from r= –1.00 to r = +1.00

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## Multiple regression

### a statistical technique, based on correlation coefficients among variables, that allows predicting a single outcome variable from more than one predictor variable

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## common-causal variable

### a variable that is not part of the research hypothesis but that causes both the predictor and the outcome variable and thus produces the observed correlation between them

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## spurious relationship

### a relationship between two variables in which a common-causal variable produces and “explains away" the relationship

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## independent variable

### an experiment is the causing variable that is created (manipulated) by the experimenter

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