What is the purpose of Meta-analysis?
- To evaluate all existing studies on a particular topic
- Answer an important question when adequate literature is available
- Report a definitive methodology for the review
- Quantify the results of studies using a standard metric
What is the process of Meta-analysis?
- Identify a problem (purpose)
- Search literature by specified means
- Review studies to determine inclusion or exclusion
- Carefully read and evaluate to identify and code important study characteristics
- Calculate effect size for dependent variables
- Apply appropriate statistical analyses
- Report all the steps and outcomes in paper
What are sources of heterogeneity?
- Study designs
- Methods for collecting data
- Definition of endpoints
- Degree of control for bias and confounding
- Instrumentation changes
Publication Bias
Occurs when studies with positive findings are more likely to be published than studies with negative findings
Qualitative Research
a method of inquiry that focuses on understanding human experiences, behaviors, and social phenomena through non-numerical data such as interviews, observation, and text analysis
Qualitative Research
Research Domains
- Naturalistic
- Interpretive
- Critical
Qualitative Research
Naturalistic
Researcher does not introduce treatments or manipulations
Qualitative Research
Interpretive
Researcher attempts to construct specific individual’s interpretations to compare differences in perspective within common experiences
Qualitative Research
Critical
Researchers conduct research to increase others’ awareness of social injustices and to encourage both participants and future readers of the findings to become committed to correcting the wrongs
Qualitative Research
Data Collection Methods
- interviews
- focus group
- observation
Qualitative Research
Interviews
Unstructured
* No formal structured instrument or protocol
* Interviewer is free to move the conversation in any direction of interest
* Particularly useful for exploring a topic broadly
Structured
* Interviewer asks the respondent the same questions in the same way
* A tightly structured schedule is used
* The questions may be phrased in order that a limited range of response may be given
Qualitative Research
Focus Groups
- A group discussion on a particular topic organized for research purposes
- Guided, monitored, and recorded by a researcher
- Members of group should have something in common
- Important to be mindful of group dynamics
Observation
- Typically takes place in natural settings and involves research taking lengthy and descriptive notes of what is happening
- Participant observers are trained in techniques of observation
- Researcher may begin as overt observer only and slowly become an observer-participant
- Sometimes obtains more reliable information about certain things (people’s behavior)
Qualitative Research - Strengths
- Data based on participants own categories of meaning
- Useful for studying a limited number of cases in depth
- Useful for describing complex phenomena
- Provides individual case information
- Can describe in rich detail phenomena as they are situated in local context
Qualitative Research - Weakness
- Knowledge produced may not be generalizable
- Difficult to make quantitative predictions
- More difficult to test hypothesis/theories
- Takes more time to collect the data
- Data analysis is more time consuming
- Results are more easily influenced by biases
Mixed Methods Research
A class of research where the researcher mixes or combines quantitative and qualitative research techniques, methods, approaches, concepts or language into single study
What are basic considerations when conducting a Mixed Methods study?
- What stage of research do you mix approaches?
- Time ordering - sequentially or concurrently?
- What approach do you emphasize more?
- How to report the data
Mixed Methods
Exploratory
qualitative –> mixing –> quantitative –> interpretation
Mixed Methods
Explanatory
quantitative –> mixing –> qualitative –> interpretation
Mixed Methods
Convergent
qualitative + quantitative –> mixing –> interpretation
