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SOWK 6003 Social Work Research Week 4 Research process, variables, hypothesis, and research designs By Dr. Paul Wong Research Process? 1. 2. 3. 4. 5. 6. 7. Problem formulation Designing the study Data collection Data processing Data analysis Interpreting the findings Writing the report Purposes of Research 1. 2. 3. 4. 5. Exploration Description Explanation Evaluation Multiple purposes This week we will focus on the first 2 steps in a research process Formulating a problem and Designing a study Operationalization of Concepts • Concept as a mental image that symbolizes an idea, an object, an event, a behavior, a person and so on……word that people agree upon to symbolize something. • Attributes are concepts that can be grouped together to form a broader concept. • Variable is - something of interest to us that can take on different values; - an element in a research project that, when measured, can take on more than one value - A variable is a characteristic that has two or more values. Relationships between Variables • Correlations • Correlational relationship simply says that two things perform in a synchronized manner. Think about this relationship! Weather and fashion, how are they relate to each other? Types of Variables Independent Variables (IVs) vs. Dependent Variables (DVs) IV is a variable that explains or causes something, and is not depending on the other variables. It is what the researcher (or nature) manipulates. DV is the variable which is the effect, being explained or caused. Extraneous Variables vs Mediating Variables • Extraneous variables represent alternative explanations for the relationships that are observed between the independent variable and dependent variables • Mediating Variable is the mechanism by which an independent variable affects a dependent variable. Sometimes it is also referred as intervening variables. How do Extraneous Variables come in to the picture between weather and fashion? Continuous, Discrete, and Dichotomous Variables Continuous variable has an infinite number of different values between the highest and lowest score. E.g., ? Discrete variable has a limited and countable number of distinct steps between the highest and lowest score. E.g.,? Dichotomous variable has only two levels. E.g.,? What is research design? http://www.csulb.edu/~msaintg/ppa696/696preex.htm When we talk about study design, we need to consider the following aspects: 1. 2. 3. 4. Nature Setting Time Participants Nature – Experimental Design - investigation that involves manipulation and control of an independent or treatment variable with the intent of assessing whether the independent variables causes a change in the level of a dependent variable. Note: Randomization : random assignment to the control and experimental group, which is not equal to random sampling. It is about the reduction of systematic error such as selection bias. – Quasi-Experimental Design - research study set up to resemble a true experiment but that does not involve random assignment of the participants to a group or manipulation and control of a true independent variable, instead relying on measuring groups based on pre-existing characteristics. (Beins, 2009) – Pre-Experimental Design - the features of experimental design and quasi-experimental design are not present. Setting • Applied Research: take place in a natural environment where people are acting as they normally do. It usually attempts to address practical questions rather than theoretical questions • Basic Research is more likely to occur in a laboratory or other controlled setting. It tests or expands on theory, with no direct application intended. (Beins, 2009) Time • One time: Cross-sectional/One shot/Posttest only • Two time: pretest – posttest design • More than two times: Longitudinal • Many many times: Time Series Participant/Subject • One person – Case study • One group – A cohort • More than one person • More than one group – Comparison study Treatment/intervention Data Source • Qualitative – – – – – – – Observations Journal/Diary/Self report Indepth Interview Focus Group Art work Archives Documents • Quantitative – Measurements through self-administered questionnaires (by hand, by mail, or online) – Interview survey (telephone, home visit) – Health indicators (BP, skin temperature, saliva cortisol etc.) Research rigor (means good standard) • Ethical Rigor - concerns about ethical consideration • Methodology Rigor 1. The matching of research questions with the research methods 2. The appropriateness and reliability of the data collection method 3. The representativeness of the samples 4. The generalizability of the data Rigor of Data Collection Method (we will talk more about them next week) Reliability : – consistency of measurement over-time (test-retest reliability) – consistency of measurement by different rater (interrater reliability) – consistency of measurement on different subgroup (split-half reliability) – consistency of measurement on items of the measurement tools (internal consistency reliability. Cronbach’s alpha) Validity: - refers to the extent to which an empirical measure adequately reflects the real meaning of the concept under consideration. • • • • • Face validity Content validity Criterion-related validity Construct validity: convergent and discriminant validity Factorial validity In class activity 1 Discussions on last week’s homework In class activity 2 How to write a research proposal?