Surveys & Experiments 1 - S.pdf

1 Surveys Today’s 2 Sampling Plan 3 Basic Experiments 1 Surveys Surveys A method to: Ask people about themselves Study relationships between and/or among variables Could be qualitative or quantitative Close-ended versus open-ended questions Surveys Surve...

1 Surveys Today’s 2 Sampling Plan 3 Basic Experiments 1 Surveys Surveys A method to: Ask people about themselves Study relationships between and/or among variables Could be qualitative or quantitative Close-ended versus open-ended questions Surveys Surveys: Issues Response sets E.g., Social desirability Tendency to answer More common for sensitive topics all questions in a particular manner Over report more acceptable (How often do you workout? Give to charity?) Under report is the opposite (How often do you smoke weed?) Constructing Good Questions Define the research objectives → questions should be linked to these Common questions includes those about attitudes and beliefs, facts and demographics, and behaviours Questions need to be worded carefully Avoid questions with: Jargon (“Do you enjoy bucolic landscapes?” vs “Do you enjoy the rolling countryside?”) Vague terms Poor sentence structure Phrasing that overwhelms Embedding misleading information Also avoid: Negative wording: worded in the negative rather than positive → makes it more confusing Unnecessary complexity: words not easily understood Double-barreled questions: having two separate questions within one question Loaded questions: contain words that might bias someone (emotional words) Rating Scales When using close-ended questions, there are various types of rating scales that could be used Rating Scales Graphic rating scale Rating Scales Semantic differential scale Rating Scales Non-verbal scale Finalizing the Survey Neatly typed, free from errors Consistent scales Ask interesting questions first Keep questionnaire as short as possible Administering the Survey Several options: In person to groups or individuals Mail surveys Internet surveys Other technologies Administering the Survey Pros Cons Less costly than Understanding interviews questions? Ensures anonymity Boredom & distraction? Are surveys given to everyone who meets the criteria of the study? Population vs Sample Population Sample Entire set of events of Drawn from a population interest Statistic – numbers Parameter – numbers summarizing a sample summarizing a population Population vs Sample “Statistics show that North American teenage girls are more likely to experience stress when viewing their FB feed” Statistics are used to make ASSUMPTIONS about populations! Surveys: Issues Cannot survey everyone; rely on sampling Make inferences about populations How confident are we about these inferences? Confidence interval - a range of plausible values for the population value Surveys: Issues Surveys: Evaluating Samples How well do the results of the research can be generalized to the intended population? External validity Surveys: Evaluating Samples Threats to external validity Sampling frame - the members of the population that are accessible to participate in your study Response rate – percentage of people who complete survey 2 Sampling Sampling Techniques Two basic techniques for sampling: Probability Non-probability sampling Sampling Techniques Probability Sampling Have list of all members of the population of interest 1. Simple random sampling 2. Stratified random sampling 3. Cluster random sampling Probability Sampling 1. Simple random sampling - every member of the population has an equal probability of being selected Probability Sampling 2. Stratified random sampling - population divided into subgroups (strata) and random samples taken from each strata Probability Sampling 3. Cluster sampling – identify non- random clusters and randomly sample from these clusters Sampling Techniques Non-Probability Sampling Don’t have a complete list of all members of the population of interest Less money, less time BUT findings may not be generalizable Sampling Techniques Non-Probability Sampling 1. Convenience sampling 2. Purposive sampling 3. Quota sampling Non-probability Sampling 1. Convenience Sampling whoever is most convenient Non-probability Sampling 2. Purposive sampling – sample meets predetermined criterion Non-probability Sampling 3. Quota sampling – sample reflects the numerical composition of various subgroups in the population Potential Exam Questions Describe reasons for conducting survey research Identify features to consider when writing questions for questionnaires and interviews, including defining research objectives, question wording, and response options Describe different ways to construct questions, including open-ended questions and closed-ended questions Potential Exam Questions Describe the ways that samples are evaluated for potential bias, including sampling frame and response rate 3 Basic Experiments Internal Validity Internal Validity Our confidence in CAUSE & EFFECT Is it that the IV causes changes in the DV? Internal Validity High Internal Validity? Well-designed and conducted experiment = confident it’s ONLY the IV causing the DV Low Internal Validity? Confound is present = NOT confident it’s ONLY the IV causing the DV Internal vs External Validity External validity Deals with generalizability → extent to which we can be sure we can generalize our results to different populations Ways to Establish Internal Validity Choose a good research design Control for extraneous variables Basic Experiments IV has 2 levels → only 2 possible groups or conditions Basic steps: 1) Select participants Probability or Non-probability sampling? 2) Assign participants to levels of the IV Random? Eliminate selection differences? (Equivalent groups?) Basic steps: 3) Introduce the IV Operational definition? 4) Measure the DV Operational definition? Basic Experiments 3 basic designs Independent groups Repeated measures Matched pairs Assigning Participants