Descriptive and Inferential Statistics in Psychology, Exams of Nursing

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PSYC 2005 Exam 1

descriptive statistics - correct answer psychologists use this to summarize and describe a group fo numbers from a research study inferential statistics - correct answer we use this to draw conclusions and make inferences that are based on the numbers from a research study but go beyond the numbers equal interval variable - correct answer variable in which numbers stand for approximately equal amounts of what is being measured (type of numeric variable) rank order variable (ordinal variable) - correct answer variable in which values are ranks (type of numeric variable nominal variable (categorical variable) - correct answer variable with values that are categories numeric variable (quantitative variable) - correct answer variable whose values are numbers levels of measurement - correct answer types of underlying numerical info provided by a measure, such as equal interval, rank order, and nominal discrete variable - correct answer variable that has specific values and cannot have values between those specific values continuous variable - correct answer variable for which, in theory, there are infinite numbers of values between any two values frequency table - correct answer ordered listing of number of individuals having each of the different values for a particular variable

grouped frequency table - correct answer frequency table in which number of individuals is given for each interval of values histogram - correct answer barlike graph of a frequency distribution in which the values are plotted along horizontal axis and height of each bar is the frequency of that value frequency distribution - correct answer pattern of frequencies over the various values; what a frequency table, histogram, or frequency polygon describes unimodal distribution - correct answer frequency distribution with one value clearly having a larger frequency than any other bimodal distribution - correct answer frequency distribution with two approximately equal frequencies, each clearly larger than any of the others multimodal distribution - correct answer frequency distribution with two or more high frequencies separated by a lower frequency rectangular distribution - correct answer frequency distribution in which all values have approximately same frequency symmetrical distribution - correct answer distribution in which pattern of frequencies on left and right side are mirror images of each other skewed distribution - correct answer distribution in which scores pile up on one side of the middle and are spread out on other side/distribution that is not symmetrical floor effect - correct answer situation in which many scores pile up at the end of a distribution because not possible to have any lower score ceiling effect - correct answer situation in which many scores pile up at the high end of a distribution because not possible to have a higher score

normal curve - correct answer specific, mathematically defined, bell shaped frequency distribution that is symmetrical and unimodal kurtosis - correct answer extent to which a frequency distribution deviates from a normal curve in terms of whether its curve in the middle is more peaked or flat than the normal curve identity (abstract number system) - correct answer each number has a particular meaning magnitude (abstract number system) - correct answer numbers have an inherent order from smaller to larger equal intervals (abstract number system) - correct answer the difference between units is the same anywhere on the scale true zero (abstract number system) - correct answer a nonarbitrary point indicating a zero level of the variable being measured scales of measurement - correct answer classification of variables into four levels, arranged from least to most closely matched with the number system nominal scales - correct answer lowest level of measurement/dont match the number system well. properties: identity. data: nominal/categorized ordinal scales - correct answer measures a variable in order of magnitude but dont provide info about differences between categories or ranks properties: identity, magnitude. data: ordered interval scales - correct answer convey info about both order and distance between values. properties: identity, magnitude, equal intervals. data: score

ratio scales - correct answer highest level of measurement. scale of measurement in which the intervals between scores are equal and the zero point on the scale represents a zero level of the quality being measured. properties: identity, magnitude, equal intervals, true zero point data: score reification of a construct - correct answer logical error in which a construct is confused for a fact inductive reasoning - correct answer reasoning from teh particualr to the general deductive reasoning - correct answer reasoning from the general to the specific eg to make predictions about future observations inductive theories - correct answer emphasizes induction, stay close to empirical data deductive theories - correct answer emphasizes deductions from constructs hypotheses are tested empirically functional theories - correct answer place approximately equal emphasis on induction and deduction model - correct answer represent reality, don't duplicate it. simplified representations of phenomena and have point to point correspondence with some of the characteristics of the phenomena. provide convenient manageable and compact representations of larger, complex, and mostly unknown reality. incomplete, tentative, and analogical. help scientists organize info, illustrate relationships, create new ideas, and produce new observations levels of constraint - correct answer degree to which the researcher imposes limits or controls on any part of the research process naturalistic observation - correct answer requires researcher to observe behavior of participants in natural environment. should do nothing to limit or change environment or behavior of participants

case study research - correct answer moving participant into a moderately limiting environment information to a slight degree, and observing participants responses correlational research - correct answer quantifying strength of relationship between two varaibles, must carefully define and precisely follow measurement procedures differential research - correct answer comparing two or more pre existing groups of participants. setting usually highly constrained and measurement procedures must be carefully defined and precisely followed experimental research - correct answer assigning participants randomly to groups and then testing each group under a different condition representative (typical) value - correct answer gives the central tendency of a group of scores central tendency - correct answer typical or most representative value of a group of scores variance - correct answer measure of how spread out a set of scores are. average of the square deviations from the mean standard deviation - correct answer square root of the variable sum of squares (SS) - correct answer sum of squared deviations computational formula - correct answer equation mathematically equivalent to the definitional formula. easier to use for figuring by hand definitional formula - correct answer equation for a statistical procedure directly showing the meaning of the procedure

z-score - correct answer number of standard deviations that a score is above/below the mean of its distributions population parameters - correct answer actual value of the mean, standard deviation, and so on, for the population sample statistics - correct answer descriptive statistics, such as the mean or standard deviations, figured from the scores in a group of people studied expected relative frequency - correct answer number of successful outcomes divided by the number of total outcomes you would expect to get if you repeated an experiment a large number of times long-run relative-frequency interpretation of probability - correct answer understanding of probability as the proportion of a particular outcome that you would get if the experiment were repeated many times subjective interpretation of probability - correct answer way of understanding probability as the degree of one's certainty that a particular outcome will occur addition rule (or rule) - correct answer used when there are two or more mutually exclusive outcomes multiplication rule (and rule) - correct answer use to figure the probability of getting both of two or more independent outcomes conditional probabilities - correct answer probability of one outcome, assuming some other outcome will happen hypothesis testing - correct answer procedure for deiciding whether the outcome of a study supports a particular theory or practical innovation

comparision distribution - correct answer distribution used in hypothesis testing represents population situation if null hypothesis is true cutoff sample score - correct answer point in hypothesis testing where if reached or exceeded by sample score, reject the null hypothesis directional hypothesis - correct answer research hypothesis predicting a particular direction of difference between populations one-tailed hypothesis - correct answer hypothesis-testing procedure for a directional hypothesis; situation in which the region of the comparison distribution in which the null hypothesis would be rejected is all on one side (tail) of the distribution nondirectional hypothesis - correct answer research hypothesis that does not predict a particular direction of difference between the population like the sample studied and population in general two-tailed tests - correct answer hypothesis testing procedure for a nondirectional hypothesis; situation in which the region of the comparison distribution in which the null hypothesis would be rejected in divided between the two sides (tails) of the distribution measurement error - correct answer distorts the scores so that the observations do not accurately reflect reality response-set bias - correct answer the tendency to respond in specific ways regardless of the situation or your experiences social desireability - correct answer tendency to respond in a socially acceptable manner. a type of response-set bias operational definition - correct answer definition of a variable in terms of the procedures used to measure and/or manipulate it

reliability - correct answer consistency interrator reliability - correct answer index of the consistency of ratings between separate rates test-retest reliability - correct answer variables that remain stable one time should produce similar scores if test participants at two different times internal consistency reliability - correct answer index of the homogeneity of the items of a measure effective range - correct answer range over which the dependent measure accurately reflects the level of the dependent variable scale attenuation effects - correct answer restricting the range of the scale might result in data that show participants bunched near top or bottom of the scale validity - correct answer how accurate predictive validiity - correct answer evaluating how well measure predicts a future event criterion - correct answer variable you want to predict predictor - correct answer variable used to predict criterion concurrent validiity - correct answer if measure is correlated with a criterion that already exists or can be measured simultaneously decision errors - correct answer right procedures leading to wrong decisions

type I error - correct answer when conclude the study supports research hypothesis when in reality research hypothesis false. alpha represents significance level of making type I error type II error - correct answer happens when set very extreme significance level. research hypothesis true but result does not come out extreme enough to reject null hypothesis. beta represents probability of making type II error effect size - correct answer measure of the differences between populations means standardized effect size - correct answer used to compare effect sizes across studies effect size conventions - correct answer standard rules about what to consider a small, medium, and large effect size, based on what is typical in psych research confidence interval - correct answer roughly, the range of the scores that is likely to include the true population mean. precisely, range of possible population means from which not highly unlikely that could obtain sample mean confidence limit - correct answer upper or lower value of a confidence interval 95% confidence interval - correct answer confidence interval in which 95% chance that the population mean falls within this interval. z scores range from +- 1. 99% confidence interval - correct answer confidence interval in which 99% chance that the population mean falls within this interval. z scores range from +- 2.