psych exam 1 key terms Flashcards
statistics
a set of mathematical procedures for organizing, summarizing, and interpreting information
population
the set of all the individuals of interest in a particular study
sample
a set of individuals selected from a population
variable
characteristic or condition that changes or has different values for different individuals
data
measurements or observations
data set
a collection of measurements or observations
datum
is a single measurement or observation and can be called (raw)score
raw score/score
a datum
parameter
a (numerical) value that describes a population
statistic
a (numerical) value that describes a sample
descriptive statistics
statistical procedures used to summarize, organize, and simplify data
inferential statistics
techniques that allow us to study samples and then make generalizations about that population
sampling error
naturally occurring error between a sample statistic and the corresponding population parameter
constructs
internal attributes or characteristics that cannot be directly observed but are useful for behavior
operational definition
it describes a set of operations for measuring a construct. It defines the contract in terms of the resulting measurements
discrete variable
separate, indivisible categories. no values can exist between two neighboring categories
continuous variable
an infinite number of possible values that fall between any two observed values. Is divisible into an infinite number of fractional parts.
real limits
the boundaries of intervals for scores that are represented on a continuous number line
upper real limit
at the top of the score of a real limit
lower real limit
at the bottom of the score of a real limit
nominal scale
consists of a set of categories that have different name. Measurements do not make any quantitative distinctions between observations
ordinal scale
a set of categories that are organized in an ordered sequence. Observed in terms of size or magnitude
interval scale
ordering categories that are all intervals of exactly the same size. (does not indicate a zero amount)
ratio scale
an interval scale with the additional feature that a score of zero indicates none of the variable being measured. (ratios of numbers do reflect ratios of magnitude)
descriptive research/strategy
measuring one or more separate variables for each individual with intent of describing the individual variables
correlation method
two different variable are observed to determine if there is a relationship between them
experiment method
one variable is manipulated while another variable is observed and measured
independent variable
the variable that is manipulated
dependent variable
Is observed to assess the effect of the treatment
control condition
individuals reciter either no treatment or they receive a neutral, placebo treatment. Used to compare with experimental condition
experimental condition
individuals who receive experimental treatment
nonequivalent groups study
pre-post study
quasi-independent variable
the “independent variable” that is used to create the different groups of scores
frequency distribution
an organized tabulation showing the number of individuals located in each category on the scale of measurement
range
group frequency distribution
class interval
apparent limits
histogram
relative frequency
symmetrical distribution
it is possible to draw a vertical lime through the middle so that one side of the distribution is a mirror image of the other
positively skewed distribution
a skewed distribution with the tail on the right hand side (points to the positive side)
negatively skewed distribution
a skewed distribution with the tail on the left hand side (points to the negative side)
central tendency
a statistical measure to determine a single score that defines the center of a distribution (find the single score)
weighted mean
bimodal
multimodal
major mode
minor mode
variability
provides a quantitative ,easier of the differences between scores in a distribution and describes the degree to which the scores are spread out or clustered together
deviation (score)
variance
equals the mean of the squared deviations. the average squared distance from the mean
standard deviation
the square root of the variance and provides a measure of the standard, or average distance from the mean
population variance (o^2)
represented by the symbol s2 and equals the mean squared distance from the mean. Is obtained by dividing the sum of squares (SS) by N
sample variance (s^2)
equals the mean squared distance from the mean. Is obtained by diving the sum of squares (SS) by n-1
degree of freedom (df)
determines the number of scores in the same that are independent and free to vary (df=n-1)
unbiased statistic
a sample statistic is unbiased if the average value of the statistic is equal to the population parameter
linear equation (correlation)
describes the relationship between X and Y. can be expressed by: Y=bX+a. Describes: direction, form, and strength or consistency
regression
technique for finding the best fitting straight line for a set of data (the straight line is a regression line)
theoretical (social research)
much of the research is concerned with developing, exploring, or testing theories or ideas that social researchers have about how the world operates
empirical research
based on direct observation and measurements of reality
casual
(pertaining to cause-effect question/hypothesis/relationship) something is casual if it leads to an outcome or makes an outcome happen
casual relationship
a cause-effect relationship
relational studies
a study that investigates the connection between two or more variables
casual studies
a study investigates a casual relationship between two variables
cross sectional study
a study that takes place at a single point in time
repeated measures
two or more waves or measurement over time
variable
any entity that can take on different values
quantitative
a numerical representation of some object. This type of variable is measured using numbers
attribute
a specific value of a variable
exhaustive
The property of a variable that occurs when you include all possible answerable responses
mutually exclusive
the property of a variable that ensures that the respondent is not able to assign two attributes simultaneously
coding
the process of categorizing qualitative data
content analysis
the analysis of text documents. Can be qualitative, quantitative, or both. Major purpose of content analysis is to identify patterns in text
exception dictionary
a dictionary that included words like “is, and, of” in a content analysis study
phenomenology
a philosophical perspective as well as an approach to qualitative methodology that focuses on peoples subjective experiences and interpretations of the world
qualitative
the descriptive nonnumerical characteristics of some objects. A descriptive nonnumerical observation
validity
the best available approximation of the truth of a given proposition, inference, or conclusion
conclusion validity
the degree to which conclusions you reach about relationships in your data are reasonable
internal validity
the approximate truth of inferences regarding cause-effect or casual relationships
construct validity
the degree to which inferences can legitimately be made from the operationalizations in your study to the theoretical constructs on which those operationalizations are based
external validity
the degree to which the conclusion in your study would hold for other persons in other places and at other times
threats to validity
reasons your conclusion or inferences might be wrong
average item-total correlation
an estimate of internal consistency reliability where you first create a total score across all items and then compute the correlation of each item with the total
average inter-item correlation
an estimate of internal consistency reliability that uses the average of the correlations of all pairs of items
Cohens Kappa
a statistical estimate of inter-rater agreement or reliability that is more robust than percent agreement because it adjusts for the probability that some agreement is due to random chance
concurrent validity
an operationalizations ability to distinguish between groups that it should theoretically be able to distinguish between
content validity
a check of the operationalization against the relevant content domain for the construct
convergent validity
the degree to which the operationalization is similar to other operationalizations to which it should be theoretically similar
criterion related validity
the validity of a measure based on its relationship to another independent measure as predicted by your theory of how the measure should behave
Cronbachs Alpha
one specific method of estimating the internal consistency reliability of a measure.
inter-rater or inter-observer reliability
the degree of agreement or correlation between the ratings or coding of two independent raters or observers of the same phenomenon
internal consistency reliability
a correlation that asses the degree to which items on the same multi-item instrument are interrelated
interval level of measurement
measuring a variable on a scale where the distance between numbers is interpretable
level of measurement
the relationship between numerical values on a measure
mono-method bias
a threat to construct validity that occurs because you use only a single method of measurement
predictive validity
a type of constrict validity based on the idea that your measure is able to predict what is theoretically should be able to predict
ratio level of measurement
measuring a variable on a scale where the distance between numbers is interpretable and there I an absolute zero value
