- Controlled experiment
A scientific process undertaken under controlled conditions. To determine the aspect under study, a few factors change from time to time with the other remaining constant. In some situations, controlled experiments do not provide a sufficient way to test the hypothesis through controlled experiment. The researcher predicts the patterns to be highlighted if the hypothesis is true. Data collection would determine the existence of the pattern.
- Observational Study
Observational studies, also referred to as epidemiological studies involve the investigator not undertaking any action on the study participants, but determining how the factors and outcomes naturally relate. The researcher observes to determine the relationship. Observational research designs are often retrospective, to determine possible causations in exposure-outcomes interactions and determine preventative measures.
- External and internal validity
Research validity denote the extent to which the results of the study participants reflect actual findings among the vast population outside the study. Validity applies to all forms of clinical studies; taking domains of internal and external validity. Internal validity refers to how the observed results reflect the truth of the population in a particular study, with the results not emanating from methodological errors. Several factors threaten a study's internal validity. These factors include erroneous participant selection, errors in measurement. It is imperative for researchers to determine how to reduce these errors to ensure the study's internal validity.
External validity is on the ability to generalize study findings, associating the patterns displayed in the sample with the entire study population. Existing biases could limit the ability to generalize sample findings to the rest of the study population.
- Measurement reliability and validity
Measurement reliability concerns the consistency denoted by the results of a particular measurement. Differentiated results within a small timeframe of undertaking a measurement lowers the measurement reliability. A measurement is unreliable if yielding different results of the same measure. Measurement validity denoted the extent to which survey aspects accurately describe the target population. This concept requires a straightforward definition of the target population. This definition portrays crucial dimensions measurable by the survey questions. This dimension's formulation is through the understanding of the research aspects to facilitate formulation of survey questions.
- Case study design
Case study design is a research method facilitating an in-depth understanding of an issue due to provision of multifaceted approaches to the issue in question. These approaches enable the understanding of difficult issues in their real-life aspect. The established nature of the case study design is attributed to its utilization in the various study disciplines. Case studies foster the explanation, description, and exploration of a phenomenon in the actual occurrence setting. Case studies can facilitate better understanding of results emanating from newly introduced polices.
- Causal design
Causal designs play an instrumental role in clearly defined problems. Specifically, the causal designs determine whether a change in one variable influences the other variables. The determined effect is termed as the cause-and –effect relationship. In determining cause-effect-relationship, three aspects need consideration. One of the aspects is that the occurring causal event must follow the occurring effect.
- Cohort design
Cohort design relate to the experimental studies as they involve comparison, exposure and unexposed. However, with cohort studies, the researcher does not decide the exposed elements. Cohort refers to a group of people. At the beginning, the study participants do not have an outcome of interest.
- Cross-sectional design
This design is a form of observational study. The researcher does not interfere with the exposure status. The investigator measures the population's exposure and outcome and could determine their relationship.
- Descriptive design
Descriptive designs vary. These designs could involve a single group's data collection through a simple descriptive study or through multifaceted studies. Simple descriptive studies focus on a single population to determine its characteristics such as the median and mean.
