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Research Design

Research Design . Procedures. Research Design. Forming your action plan Deciding on the Who and When Defining all concepts and terms. Research Design. Three purposes for research: Exploration Description Explanation Or Descriptive- existing conditions Normative- observed vs. intended

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Research Design

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  1. Research Design Procedures

  2. Research Design • Forming your action plan • Deciding on the Who and When • Defining all concepts and terms

  3. Research Design • Three purposes for research: • Exploration • Description • Explanation • Or • Descriptive- existing conditions • Normative- observed vs. intended • Impact- can it be attributed to programs?

  4. Exploration • To gain familiarity with a topic • Typically done to: • Satisfy a researcher’s curiosity and desire to understand • “Test the water” for a more extensive study • Develop methodology to be used in a subsequent study

  5. Description • Provide context for situations and events • Typically based on observation and reporting • Observation is systematic • Example: U.S. Census

  6. Explanation • Attempts to address the question of “why” • Tries to get at reasons and underlying causes • Example: Not “would you vote for McCain” but “why would(n’t) you vote for McCain?”

  7. GAO- Designing Evaluations • Considerations • Kind of information to be acquired • Sources of information (i.e. types of respondents) • Methods of sampling (i.e. random) • Methods of collecting data (i.e. interviews, surveys) • Timing and frequency of information collection • Basis for comparing outcomes • Analysis plan

  8. Research Design: Experiments • Experiments aim to control one variable or set of variables in order to determine their relationship to and/ or impact on another set of variables. • Types of studies: • Experiment • Uses a random sample • Quasi-experiment • Does not use a random sample, must try to correct for error through statistical tests

  9. Impact of a Program/Service Involving an Experimental Design IMPACT = Outcome of experimental group receiving the treatment compared to control group Information Literacy Instruction

  10. Classic Design • Two group pre- and post- test • One experimental group • One “untreated” control group • Compare outcomes to assess impact • Problems with this?

  11. Solomon 4 Group Test • Classic Design expanded to include two sets: • One set has experimental group and control group who both receive pre- and post-tests • One set has experimental group and control group who receive only post- tests. • Advantages over classic model?

  12. Solomon Four Group Design Before Treatment After Group 1 no yes yes Control 1 no yes yes Group 2 yes yes yes Control 2 yes no yes

  13. Time Series Design • Repeats testing twice (or more) to establish a trend in the data independent of the experiment Pretest Treatment Posttest Pretest Treatment Posttest REPEAT Experiment yes yes yes yes yes yes Control Group yes no yes yes no yes

  14. EXAMPLES • Pretest/posttest design with control group pretest treatment posttest Experiment yes yes yes Control Group yes no yes Pretest/posttest design without control group pretest treatment posttest Experiment A yes yes yes Experiment B yes yes yes

  15. Case Study • Basis of selection: representative, typical, cluster, probability, etc. • Multiple methods of data collection

  16. Populations and Statistical Sampling

  17. Populations • Population- the entire group/ universe under study • Sample- a portion of a population of possible information sources • Sampling- methods for selecting these sources

  18. Research Design: Action Plan (continued) • Who is studied • population • Sample • Is sample reflective of population? • Where • Sampling? • When • Sampling?

  19. Who (or What) is being studied? • Units of analysis: the what or whom being studied. In social research the most typical units of analysis are individual people. • Can be: individuals, groups, organizations, social interactions, social artifacts • Examples: • Library Users or Non-Users • First-year Students • Senior Citizens • Public Libraries • Also • ILLs • Biographies, Mysteries, Audiobooks (i.e. collections) • Web sites

  20. Beware: Pitfalls of Analysis • Ecological Fallacy: • Something learned about a group says something about the individuals making up that group. • Reductionism • An attempt to explain phenomena in terms of limited or lower-order concepts.

  21. Who is being studied • How to select a sample?

  22. Sampling- Three Options • Census- collecting information from the entire group making up a population • Like the decennial census • Judgment sampling- making conscious choices • Convenience Sampling- what’s available • Probability/ Statistical Sampling- left to chance, each member of a population has an equal chance of being chosen

  23. Sampling: Purpose • Representativeness • Sample has roughly the same distribution of characteristics as the population from which it is drawn. • Nevertheless, each sample will differ from each other, as well as from the population • Can determine the amount of error

  24. Probability Sampling (1) • Random sampling: Each member of the population has an equal and known probability of being selected • Systematic sampling: Each member of the population is either assembled or listed, a random start is designated and then members of the population are selected at equal intervals… nth intervals

  25. Probability Sampling (2) • Stratified: Each member of the study population is assigned to a group or stratum, then a simple random sample is selected from each group or stratum

  26. Probability Sampling (3) • Cluster: Each member of the study population is assigned to a geographically-defined group or cluster. Clusters are then selected at random, and members of a selected group are represented in the sample. • http://www.claritas.com/MyBestSegments/Default.jsp • Role of GIS and TIGER files • http://www.census.gov/geo/www/tiger/index.html

  27. Non-probability Sampling • Convenience: selecting cases based on their availability • “Typical” cases: selecting cases already known and not considered “extreme” • Snowball: group members identify additional members to be included in sample • Quota: sample is in same proportion as population

  28. How selected Sample size Determine the actual individuals or “things” included The Sample

  29. Sample Size • A larger sample does not necessarily mean better results, but • Too small a sample can lead to error

  30. Sample Size- 3 Considerations • Precision (sampling error)- the range in which the “true value” is estimated to be: ±5 • Confidence Level (Central Limit Theorem)- when a population is repeatedly sampled, the average value is = to the true value, and values in each survey will be normally distributed: 95% confidence level • Degree of Variability- distribution of attributes within a population. The more homogenous the population, the smaller the sample size.

  31. Sample Sizehttp://edis.ifas.ufl.edu/PD006#TABLE_1

  32. Sampling Customers (Example) • Present • Lost • Never-gained • Nonuser

  33. Users/Uses of Electronic Resources (More Examples) • Home page users in general • Users of a database

  34. Questions of When • How might time effect our study? • How do we choose a time frame? • What is an appropriate time frame based on the research problem? • Address time through: • Cross-sectional studies • Longitudinal studies

  35. Cross-Sectional Studies • A study based on observations representing a single point in time. • A “snapshot” • Best for exploratory and descriptive studies • U.S. Census • Explanatory cross-sectional studies aim at drawing causal relationships over time based on observations made at one time. • Issues?

  36. Longitudinal Study • Permits observations of the same phenomena over an extended period. • Researcher may “follow” a group over time • Researcher may become part of a group • Researcher may study artifacts developed over time

  37. Types of Longitudinal Studies • Trend Studies • Type of longitudinal study that examines changes within a population over time • Cohort Studies • Examines a specific subpopulation (cohort) as they change over time- often based on age. • Panel Studies • Examines the same set of people over time

  38. The Learning Organization • http://www.lib.umd.edu/groups/learning/learningorg.html

  39. Group Activity Selecting a Sample • Archive/ Special Library • Public Library • Academic Library/ School Library • Identify a research question • Define your population • Describe how you would select a sample • Could you design an experiment around this project?

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