Ch 2 Flashcards
Anecdotal evidence
personal stories about scientific incidents and experiments
Case study
in-depth investigation of an individual subject
Confounding of variables
occurs when two variables are linked together in a way that makes it difficult to sort out their specific effects
Control group
subjects who do not receive the treatment given to the experimental group
Correlation
two variables are related to one another
Correlation coefficient
a numerical index of the degree of a relationship btw two variables
Subjects
same as participants
Dependent variable
variable that is thought to be affected by manipulation of the IV
Descriptive statistics
used to organize and summarize data
central tendency (mean, median, mode), variability, coefficient of correlation
Double-blind procedure
research strategy in which neither subjects nor experimenters know which subjects are in experimental or control groups
Experimental group
subjects who relieve some special treatment in regard to the IV
Independent variable
condition or event that the experimenter varies in order to see its impact on another variable
Experimenter bias
occurs when a researcher’s expectations or preferences about the outcome of a study influence the results obtained
Naturalistic observation
a researcher engages in careful observation of behaviour without intervening directly with the subjects
Frequency distribution
orderly arrangement of scores indicating the frequency of each score or a group or scores
Frequency polygon
line figure used to present data from a frequency distribution
Survey
researchers use questionnaires or interviews to gather info about specific aspects of participants’ behaviour
Mean
arithmetic average of the scores of distribution
Inferential statistics
used to interpret data and draw conclusions
used to evaluate the possibility that results might be due to chance
Mode
most frequent score in the distribution
Statistics
the use of mathematics to organize, summarize, and interpret numerical data
Negatively skewed distribution
scores pile up at the high end of the scale
extreme low scores pull the mean down
Meta analysis
combination of statistical results of many studies of the same question, yielding an estimate of the size and consistence of a variable’s effects
Percentile score
indicates the percentage of people who score at or below a certain score
Positively skewed distribution
scores pile up at the low end of the scale
extreme high scores inflate the mean
Standard deviation
an index of the amount of variability in a set of data
Statistical significance
probability that observed findings are due to chance is very low
Variability
how much the scores in a data set vary from each other and from the mean
Placebo effects
occur when participants’ expectations lead them to experience some change even though they receive a placebo treatment
Population
large collection of animals or people (from which a sample is drawn) that researchers want to generalize about
Replication
repetition of a study to see whether the earlier results are duplicated
Response set
tendency to respond to questions in a particular way that is unrelated to the content of the questions
Sample
collection of subjects selected for observation in an empirical study
Sampling bias
a sample is not representative of the population from which it was drawn
Social desirability bias
tendency to give socially approved answers to questions about oneself
