Chapters 2.2 and 2.4 Flashcards
What is a research design?
a set of methods that allows a hypothesis to be tested, have a few characteristics in common: Variables, operational, definitions, and data
what is a case study?
an in depth report about the details of a specific case.
naturalistic observations
an alternative form of descriptive research is to observe people or animals in there natural setting.
what is the self reporting method?
a method in which responses are provided directly by the people who are being studied.
correlational research
involves measuring the degree of association between two or more variables.
correlation coefficient
0= no relationship -1= means strong negative correlation \+1= strong positive correlation
third variable problem
the possibility that a third, unmeasured variable is actually responsible for a well-established correlation between 2 variables
random assignment
a technique for dividing samples into two or more groups in which participants are equally likely to be placed in any condition of the experiment.
confounding variable
is a variable outside of the researchers control that might affect or provide an alternative explanation for the results.
independent variable
the variable that the experimenter manipulates to distinguish between 2 or more groups.
dependent variable
the observation or measurement that is recorded during the experiment and subsequently compared across all groups.
Quasi-experimental research
is a research technique in which the two or more groups that are compared are selected based on pre determined characteristics.
descriptive statistics
a set of techniques used to organize, summarize and interpret data to give the big picture of the results.
frequency
the number of observations that fall within a certain category or range of scores.
normal distribution
a symmetrical distribution with values clustered around a central, mean value.
central tendency
a measure of the central point of a distribution. there are three different measures: mean, median, and mode.
Mean
the arithmetic average of a set of numbers.
- sum of all numbers divided by amount of numbers
median
the point on the horizon where 50% of numbers are lower, and 50% are higher.
- the score in the middle of the distribution
mode
the category with the highest frequency
- the most common number.
variability
the degree to which scores are dispersed in a distribution. in other words, some are more spread out while others are more clustered.
standard deviation
it is an estimate of the average distance from the mean.
how to find the average deviation?
- find mean of a set of values
- find deviation from mean (individual values subtracted from mean)
- find sum of deviations squared
- find variance = sum of squared deviations divided by # of original values
- SD= square root of variance
hypothesis test
a statistical method of evaluating whether differences among groups are meaningful, or could have arrived by chance.
Statistical significance
is a concept that implies that the means of a the groups are farther apart than you would expect them to be by random chance alone.
null hypothesis
assumes that any differences between groups or conditions are due to chance.
experimental hypothesis
assume that any differences are due to a variable controlled by the experimenter.
P-value
the probability of results being due to chance is known as the p value. it is recommended that researchers use p<5% as the cut off point to ensure accurate results.
