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© 2011 Pearson Education, Inc. All rights reserved. Recall The Research Types & Their Focus Ethnographic—social behavior Historical—past events Survey—describing characteristics Correlational—predictive relationships Causal-comparative—possible causation Experimental/Quasi-Experimantal—causation or possible causation Mixed-Methods—topics requiring both qualitative and quantitative data Action—innovation or local problems Evaluation—judgment about quality 2

© 2011 Pearson Education, Inc. All rights reserved. Types of Data Needed Descriptions —verbal representations of participants, etc. Scores —numerical values assigned to test performance Measurements —numerical values resulting from instruments other than tests Opinions —views expressed by participants and informants Statements —authoritative verbal opinions Analyses —clarification reached through logic 3

© 2011 Pearson Education, Inc. All rights reserved. Sources of Data Participants —individuals specially selected to take part in the research Procedures —formalized ways of operating in educational settings Settings —specific environments in which the behavior being investigated occurs Objects —inanimate things Records —highly detailed reports Documents —written papers or reports in their entirety Informants —people other than participants 4

© 2011 Pearson Education, Inc. All rights reserved. Samples and Their Selection Questions to consider… »Are samples necessary? »Can small samples adequately represent large populations? Probability sampling —can specify the probability of selection for each member of a population » Random sampling » Stratified random sampling » Cluster sampling » Systematic sampling * 5

© 2011 Pearson Education, Inc. All rights reserved. Samples and Their Selection (cont’d.) Nonprobability sampling —probability of inclusion into a sample cannot be specified » Convenience sampling » Judgment (a.k.a., purposive) sampling » Snowball (a.k.a., network or chain) sampling » Quota sampling » Systematic sampling * 6

© 2011 Pearson Education, Inc. All rights reserved. Size of Samples Descriptive research—10%–20% of the population (1%–5% for extremely large populations) Correlational research—minimum of 30 participants Causal-comparative & experimental research—minimum of 15 per group REMEMBER...A carefully selected small sample is better (i.e., more representative ) than simply increasing the size of a sample 7

© 2011 Pearson Education, Inc. All rights reserved. Validity & Reliability in Data Collection Validity of data — whether or not the data measure what they purport to measure Sources of validity evidence (ways of determining if data are valid) for test data: » Evidence based on test content » Evidence based on response processes » Evidence based on internal structure » Evidence based on relations to other variables » Evidence based on consequences of testing Types of validity for non-test data: » External criticism — authenticity 8

© 2011 Pearson Education, Inc. All rights reserved. Validity & Reliability in Data Collection (cont’d.) Reliability of data — whether or not the data are being measured consistently Types of reliability (ways of determining if data are reliable) for test data: » Test-retest method » Equivalent forms method » Split-half method » Internal consistency Types of validity for non-test data: »Examine consistency of data 9

© 2011 Pearson Education, Inc. All rights reserved. Procedures in Data Collection Methods of actually collecting data: »Notation »Description »Analysis »Questioning ◊Interviews (structured, semi-structured, open- ended) ◊Surveys (Likert scale, Likert-type scale, others) ˜Cross-sectional ˜Longitudinal »Testing »Measurement 10

© 2011 Pearson Education, Inc. All rights reserved. A Composite of Data Collection Procedures See Flow Chart on p

© 2011 Pearson Education, Inc. All rights reserved. Dr. Trochim’s discussion of sampling terminology (socialresearchmethods.net/kb/sampterm.htm)socialresearchmethods.net/kb/sampterm.htm Dr. Trochim’s discussion of probability sampling techniques (socialresearchmethods.net/kb/sampprob.htm)socialresearchmethods.net/kb/sampprob.htm Dr. Trochim’s discussion of nonprobability sampling techniques (socialresearchmethods.net/kb/sampnon.htm)socialresearchmethods.net/kb/sampnon.htm Dr. Trochim’s discussion of how to construct a survey (socialresearchmethods.net/kb/survwrit.htm)socialresearchmethods.net/kb/survwrit.htm Types of questions that can be used in survey research (socialresearchmethods.net/kb/questype.htm)socialresearchmethods.net/kb/questype.htm Methods of structuring response formats for surveys (socialresearchmethods.net/kb/quesresp.htm)socialresearchmethods.net/kb/quesresp.htm Ways to word questions in order to avoid misinterpretation (socialresearchmethods.net/kb/quesword.htm)socialresearchmethods.net/kb/quesword.htm Suggestions on where to place specific types of questions within the actual survey (socialresearchmethods.net/kb/quesplac.htm)socialresearchmethods.net/kb/quesplac.htm Educational Testing Service (ETS) Test Collection ( Mental Measurements Yearbook’s Test Reviews Online (buros.unl.edu/buros/jsp/search.jsp)buros.unl.edu/buros/jsp/search.jsp) 12 Applying Technology… Web sites covering topics related to data collection