PSCH 242 UIC EXAM 2 CORRECT ANSWERS GRADED A 2025 UPDATED

Z score - -a measure used to compare data across different studies/experiments This is for professor _________'s class - -c h e n Z score formula - -(x- mean)/sd Positive skew - -skew right Negative skew - -skew left What are the percentages for the normal distribution - -between -1 and 1: 68% Between -2 and 2: 95% Between -3 and 3: 99.7% T score use - -when comparing two sets of scores T score formula - -(x- mean)/s, s is the estimation of standard deviation (population sd) ___-score is more commonly used that __-score because ______ - -t,z, bc the z score uses the real mean and we can never know the true mean for some populations, the t score estimates the mean so it is more realistic What is the alpha-value used in psychology - -alpha=0.05 Null hypothesis - -states there is no difference between two means You can either ____ or _____ the null hypothesis - -reject, fail to reject Research hypothesis - -- alternative hypothesis - there is a different between the two means Type 1 error - -you reject a tru null hypothesis Type 2 error - -you fail to reject a not ture null hypothesis Single sample t test - -compares a sample against a population PSCH 242 PSCH 242 PSCH 242 Paired-sample t test (dependent sample t test) - -when each participant is measured twice and the two scores are compared Independent sample t test - -when comparing the scores of two independent populations to determine whether there is statistical difference that they are different Anova - -- anaysis of variance - test the mean differences between 2+ groups Anova general formula - -(between group variance)/ (within group variance) ______ can alwayys replace _______ but ______ cannot always replace _______ - anova can alwyas replace a t-test but t-test cannot always replace anova Power - -the probability of rejecting te null hypothesis when it is false One way to always increase power - -increase the sample size Effect size - -the magnitude of a relationship between two or more variables Correlation - -a measure of the relationship between two variables Correlation is only applicable to ____ relationships - -linear Linear regression - -line of best fit Low constraint methods - -- when researchers have low control over extraneous variables in an experiment - harder to design and implement than high-constraint methods - general hypothesis - unable to test causal relationships Examples of low-constraint methods - -- naturalist observations - field experiments - case studies - archival research Reasons for using low constraint methods - -- exploratory work (generally unfamiliar with concept/population) - testing generealizability of lab research to real populations - testing new procedure/technique Archival research - -- going back and reading the archives from primarcy sources on a topic - cons: time consuming PSCH 242 PSCH 242 Case study - -- studying the development of a specific person or group over time the exhibits a phenomenal thing - cons: not generalizable, time consuming Field experiment - -- testing an intervention in the real world instead of a lab - cons: lacks randomization, not very replicable, difficult to get informed consent In low constraint methods, the sample is often not under the experimenter’s' control so this leads the results to lack ______ . - -generalizability Sampling situations and behaviors - -- important to consider the representativeness of the sample in relation to the situation Unobtrusive measures - -- when participants are unaware of the actual behavior being measured - reduces measure reactivity Natural erosion - -- measuring the natural change/wear of something overtime with a set start and endpoint - eg. Measuring the wear of a museum exhibit over a months time Controlled erosion - -- measuring the effectiveness of an erosion technique by intentionally eroding something and then using a device to quantify the results Accretion - -- measures physical traces of behavior - eg. Using pencil marks to measure pencil chewing Archival records are a form of __________ ___________ - -unobtrusive measures Simple observation - -unobtrusive observation of events without any attempt to affect them Contrived observation - -- using hardware or participant observation to measure a variable - hardwaer = videotaping or sum - participant = the reaction of one person to measure the behavior of another (eg. Car honking to measure delay of starting to drive when the light turns green) Ethical issues w/ unobtrusive measures - -- no informed consent - data in archival records may be sensitive Ways to avoid ethical violations in unobtrusive measures - -- use public places - post warnings - ask for permission after they have been measured PSCH 242 PSCH 242 Low contstraing method cons - -- bad representativeness (sample not a reflection of the population) - not very replicable - limitations of the observer (bias) - cannot be used to gain evidence of causal relationships - ex post facto fallacy (assumption of causality using past and current events) - not applicable to samples that are not similar to the sample used Why do low constraint methods have poor replicability - -- procedures are not heavily specified and often change as the study progresses - procedures are often unique to the observer Medium constraint methods - -- between field and lab research - cant be used to prove causal relationships Medium constraint methods are easy to ____________ but hard to __________ . - design and conduct, analyze and interpret Steps to conduct correlational research - -1. Develop the problem statement 2. Obtain the sample 3. Measure the variables 4. Analyze data 5. Interpret results Extreneous variable - -- an unaccounted for variable that influences both the independent and dependent variable R^2 - -- coefficient of determination - measures the fit of the model to the data - Quasi experiment - -- compares 2+ preexisting groupds (eg. Gender, race, disease patients) - aka differential research Difference between quasi experiment and ture expriment - -ina quasi experiment, there are extraneous variables that cannot be controlled Cross-sectional study - -- studying how different generations currently behave Longitudinal study - -- repreated observations of the same variable, in the same sample, over time Where do the setps of conducitng correlational research differ from the steps of conducting differential research - -in differential research, you must determine the appropriate comparison groups after developing a problem statement PSCH 242 PSCH 242 Extraneous/confounding variables are not applicable to ________ research - correlational What type of analysis should be used when analyzing score data in differential research - -t-test or anova What type of analysis should be used when analyzing ordinal data in differential research - -mann-whitney u-test What type of analysis should be used when analyzing nominal data in differential research - -chi-square When can correlational and differential techniques be used to approximate causal relationships - -when an experiment would be unethical In psychology, most correlational data are collect via ____________________ - questionnaire Core construct (questionaire) - -- the central issue to be measured - best to only hav eone per questionnaire Pros and cons of open-ended questions - -- pros: no researcher bias, felxible -cons: need to code(interpret) data Pros and cons of close-ended questions - -- pros: no need to code data, researcher control - cons: answers limited to researcher's vision Are open or closed questions more common in psychology questionnaires - -closed Likert scale - -- when participants state how much they agree/disagree with a given satement - most common scale in questionnaire research - eg. 1. Strongly disagree, 2. Disagree, 3. Neither... Does it matter whether you use an odd or even number of scale options with the likert scale ? - -yes. - odd number allows for an indifferent option (3. Neither agree nor disagree) - even number forces ppl to chose a side with only 4 options (strongly agree/disagree and agree/disagree) Dichotomous scale - -- a type of likert scale - a simple yes/no Pilot study - -- the pre-testing of a questionnaire t