Biomedical subjects

R Behi

Publications and source records attributed to R Behi.

30 records · Page 2Linked to original sources

PubMedDate not supplied

Single-case experimental designs. 1: Using idiographic research.

The single-case experimental design is an example of idiographic research which involves establishing causality. The reasons for using idiographic research in nursing are discussed and important differences between nomothetic and idiographic designs are highlighted in this article. Single-case experimental designs are recommended in situations where both true experimental and quasi-experimental designs are difficult or impossible to use for practical or ethical reasons. Single-case experimental designs are ideal for nursing care situations because they study individual cases, making it possible to give individualized nursing care while simultaneously studying the outcomes of specific patients.

Humans↗

PubMedDate not supplied

Causality and control: key to the experiment.

The main aim of the experimental approach in research is to discover causal relationships between variables. This article describes the concept of causality and discusses common and important aspects and factors related to causality, manipulation and control. The four principles which underpin the inference of causality in experiments are highlighted and the role of 'control' in achieving the aim of experimental studies is discussed. Some methods of control such as manipulation, randomization, matching subjects, and holding extraneous variables constant are considered. Experimental designs are underpinned by these concepts. Indication is given of the threats to internal validity, which will be discussed in detail in the next article in this series.

Causality↗

PubMedDate not supplied

Causality and control: threats to internal validity.

The essence of experimental research is to establish causal relationships between variables and this requires internal validity. An experiment is said to have internal validity when extraneous variables have been controlled. However, there are many threats to internal validity. This article considers 13 of them, providing examples which clarify and help to identify under what conditions these threats may occur. The threats discussed are history, maturation, testing, instrumentation, statistical regression, selection mortality, interactions with selection ambiguity about the direction of causal influence, diffusion of imitation of treatments, compensatory equalization of treatments, compensatory rivalry by respondents receiving less desirable treatments and resentful demoralization of respondents receiving less desirable treatments.

Bias↗

PubMedDate not supplied

The basic experimental design.

This article considers the three characteristics of the basic experiment (random assignment of subjects, manipulation of relevant variables and control of irrelevant variables) and describes the two most common experimental designs: the pre-test/post-test design and the post/test only design. The necessity of controlling for subject and situational variables is highlighted and the challenge researchers face when using experimental approaches in other than laboratory situations are addressed briefly.

Controlled Clinical Trials as Topic↗

PubMedDate not supplied

Single-case experimental designs. 2: Common examples.

This article describes and discusses some commonly used single-case experimental designs, including reversal and non-reversal designs. The A-B-A-B design is recommended for use when reversal designs can be used and when the patient's treatment phase needs to be maintained. The B-A-B design is used in situations when studying an intervention or treatment which is already in progress. The A-B1-A-B2-A-Bn design is useful when the aim of the researcher is to study the effects of different levels of a specific independent variable. Two types of non-reversal multiple baseline designs are discussed here.

Data Interpretation, Statistical↗

PubMedDate not supplied