Overview of Research Design Features

Group F-b

Intervention

Key Questions:• Will there be an intervention?• What will the intervention entail?• What specific design will be used?

Intervention

Design Options:• Experimental Research Design -

This design is most appropriate in controlled settings such as laboratories.

• The design assumes random assignment of subjects and random assignment to groups (E and C).

Experimental Design

• It attempts to explore cause and affect relationships where causes can be manipulated to produce different kinds of effects. Because of the requirement of random assignment, this design can be difficult to execute in the real world (non laboratory) setting.

Quasi Experimental Research Design

•  This research design approximates the experimental design but does not have a control group. There is more error possible in the results. 

Non-experimental Research Design

• Take people as they are and measure them

• Have already conducted one type: Correlation– (terminology and use of correlational

study to refer to non-experimental)

Developmental or Time Series Research Design

•  Data are collected at certain points in time going forward. There is an emphasis on time patterns and longitudinal growth or change.

Causal Comparative or Ex Post Facto Research

Design• This research design attempts to

explore cause and affect relationships where causes already exist and cannot be manipulated. It uses what already exists and looks backward to explain why.

Descriptive or Survey Research Design

• It attempts to describe and explain conditions of the present by using many subjects and questionnaires to fully describe a phenomenon.

Case and Field Research Design

• Also called ethnographic research, it uses direct observation to give a complete snapshot of a case that is being studied. It is useful when not much is known about a phenomenon. Uses few subjects.

Historical Research Design

• The purpose is to collect, verify, synthesize evidence to establish facts that defend or refute your hypothesis. It uses primary sources, secondary sources, and lots of qualitative data sources such as logs, diaries, official records, reports, etc. The limitation is that the sources must be both authentic and valid.

Correlational or Prospective Research

Design • It attempts to explore relationships

to make predictions. It uses one set of subjects with two or more variables for each.

EXTRANEOUS (CONFOUNDING)

VARIABLESit should be extraneous to the

purpose of a specific study/• There are a number of ways to

control such influences, but the general principle in the extraneous variables must be held constant.

MASKING or BLINDING

• It is sometimes used to avoid biases stemming from participants’ or research agents’ awareness of study hypotheses or research status.

• 2 types: • Single-blind studies – involve masking

for one group• Double-blind studies – involve masking

of two groups

Comparisons

• It provides a context for interpreting results.

• Most research questions are phrased in terms of comparison because the comparison typically embodies the independent variable.

Various Types of Comparisons

• Comparison between two or more groups – In an intervention study, we might want to compare those receiving the special intervention with those receiving “usual care.”

Various Types of Comparisons

• Comparison of one group’s status at two or more points in time – e.g. We might want to compare patients’ levels of stress before and after introducing a new procedure to reduce preoperative stress.

Various Types of Comparisons

• Comparison of one group’s status under different circumstances – e.g. We might compare people’s heart rates during two different types of exercise.

Various Types of Comparisons

• Comparison based on relative rankings

- This research question involves a comparison of those with different rankings, higher versus lower-on both variables.

Various Types of Comparisons

• Comparison with other studies- Researchers may directly compare

their results with results from other studies, sometimes using statistical procedures.

Research Location

• An important task during the planning phase is to identify the sites (and settings) for the study.

• Planning for this aspect of the study involves two types of activities:

1. selecting the site/sites, and 2. gaining access to them.

Site Selection

• The site must be appropriate for the research question, that is whether it is likely to have people with the behaviors, experiences, or characteristics of interest.

Site Selection

• Must have sufficient number of these kinds of people and adequate diversity of mix of people to achieve research goals.

• Entry must be possible and access to study participants can be granted.

Site Selection

• Should also be one that matches other requirements, such as, space needs, personnel, laboratory facilities, and so forth.

• Researcher must be allowed to maintain an appropriate role vis-à-vis study participants for the duration of the study.

Gaining Access

• If the site is an entire community, a multi-tiered effort of gaining acceptance from gatekeepers may be needed.

• Establishment of trust is a central issue, gaining entrée requires strong interpersonal skills as well as familiarity with the customs and language of the site.

Gaining Access

• Gatekeepers need information on which to base their decision about granting access, and this information usually should be put in writing, even if the negotation takes place in person.

Gaining Access

• The letter of information sheet should cover the following points:

1. The purpose of the research, and who the beneficiaries would be

2. Why the site was chosen or is considered desirable.

Gaining Access

3. What the research would entail, including when the study would start, how long research staff would be at the site, how much disruption there likely would be, and what the resource requirements are

4. How ethical guidelines would be maintained.

5. What the gatekeeper or others at the site have to gain from cooperating in the study.

Timeframes

• Research design also designates when, and how often, data will be collected.

• Data are collected from participants at a single point in time.

• Some call for multiple contacts with participants to determine how things have changed over time.

Cross-sectional designs

• Involve the collection of data once: the phenomena under study are captured during one period of data collection.

• Appropriate for describing the status of phenomena or for describing relationships among phenomena at a fixed point in time.

Longitudinal Design

• A study in which data are collected at more than one point in time over an extended period.

• Four situations call for longitudinal design:

1. Studying time-related processes.2. Determining time sequences.3. Making comparisons over time.4. Enhancing research control.

Organization of a Research Project

• Researchers sometimes develop visual timelines or charts to help them organize the study.

Project timeline

1. Research question (Problem Identification)2. Literature Review3. Clinical fieldwork4. Theoretical framework5. Hypothesis6. Research design7. Intervention protocols8. Population specification9. Sampling plan10. Data collection plan

Project timeline

11. Ethics procedures12. Finalization of plans13. Collection of data14. Data preparation15. Data analysis16. Interpretation of results17. Presentations/reports18. Utilization of findings

Pilot Study

• Is a small-scale version or trial run designed to test the methods to be used in a larger, more rigorous study, which is sometimes referred to as the parent study.

• Purpose of pilot study is to prevent an expensive fiasco-the misfortune of undertaking a costly but flawed largescale study.

• A.k.a feasibility studies.

Critiquing planning aspects of a study

1. Evidence in a report that the study was carefully conceptualized.

2. Readers can consider whether the researcher’s plans reflect adequate attention to concerns about EBP.

3. Evidence that the researcher devoted sufficient time and resources in preparing for the study