Methodology & Statistics Flashcards
scientific method
system of gathering data so that bias and error in measurement are reduced
hypothesis
tentative explanation of a phenomenon based on observations
replication in research
repetition of a study or experiment to see if the same results will be obtained in an effort to demonstrate reliability of results
What are the 5 steps of the scientific method?
1) Perceiving the question, 2) Forming a hypothesis, 3) Testing the hypothesis, 4) Drawing conclusions, 5) Reporting your results
observer effect
tendency of people or animals to behave differently from normal when they know they are being observed
participant observation
a naturalistic observation in which the observer becomes a participant in the group being observed
observer bias
tendency of observers to see what they expect to see
case study
study of one individual in great detail
representative sample
randomly selected sample of subjects from a larger population of subjects
population
the entire group of people or animals in which the researcher is interested
correlation
a measure of the relationship between two variables
correlation coefficient
a number derived from the formula for measuring a correlation and indicating the strength and direction of a correlation
experiment
a deliberate manipulation of a variable to see if corresponding changes in behavior result, allowing the determination of cause-and-effect relationships
operational definition
definition of a variable of interest that allows it to be directly measured
independent variable
variable in an experiment that is manipulated by the experimenter
dependent variable
variable in an experiment that represents the measurable response or behavior of the subjects in the experiment
experimental group
subjects in an experiment who are subjected to the independent variable
control group
subjects in an experiment who are not subjected to the independent variable and who may receive a placebo treatment
random assignment
process of assigning subjects to the experimental or control group randomly, so that each subject has an equal chance of being in either group
placebo effect
the phenomenon in which the expectations of the participants in a study can influence their behavior
experimenter effect
tendency of the experimenter’s expectations for a study to unintentionally influence the results of the study
single-blind study
study in which the subjects do not know if they are in the experimental or the control group
double-blind study
study in which neither the experimenter nor the subjects know if the subjects are in the experimental or control group
critical thinking
making reasoned judgments about claims
descriptive statistics
a way of organizing numbers and summarizing them so that patterns can be determined
inferential statistics
statistical analysis of two or more sets of numerical data to reduce the possibility of error in measurement and to determine if the differences between the data sets are greater than chance variation would predict
statistic
a measure of central tendency or variability computed from a sample
sample
group of subjects selected from a larger population of subjects, usually selected randomly
parameter
a number representing some measure of central tendency or variability within a population
statistics
branch of mathematics concerned with the collection and interpretations of numerical data
frequency distribution
a table or graph that shows how often different numbers or scores appear in a particular set of scores
histogram
a bar graph showing a frequency distribution
polygon
line graph showing a frequency distribution
normal curve
a special frequency polygon in which the scores are symmetrically distributed around the mean, and the mean, median, and mode are all located on the same point on the curve, with scores decreasing as the curve extends from the mean
bell curve
alternate name for the normal curve, which is said to be shaped like a ball
skewed distribution
frequency distribution in which most of the scores fall to one side or the other of the distribution
negatively skewed
a distribution of scores in which scores are concentrated in the high end of the distribution
positively skewed
a distribution of scores in which scores are concentrated in the low end of the distribution
bimodal distribution
frequency distribution in which there are two high points rather than one
measure of central tendency
numbers that best represent the most typical score of a frequency distribution
mean
the arithmetic average of a distribution of numbers
median
the middle score in an ordered distribution of scores, or the mean of the two middle numbers; the 50th percentile
mode
the most frequent score in a distribution of scores
bimodal
condition in which a distribution has two modes
measures of variability
measurement of the degree of differences within a distribution or how the scores are spread out
range
the difference between the highest and lowest scores in a distribution
standard deviation
the square root of the average squared deviation from the mean of scores in a distribution; a measure of variability
statistically significant
referring to differences in data sets that are larger than chance variation would predict
t-test
type of inferential statistical analysis typically used when two means are compared to see if they are significantly different
significant difference
a difference between goups of numerical data that is considered large enough to be due to factors other than chance variation
correlation coefficient
a number that represents the strength and direction of a relationship existing between two variables
