The best evidence for causal claims usually comes from experiments involving direct manipulation of the independent variable.
Weaker support can come from research statistically controlling for extraneous variables and longitudinal studies.
Selective description of specific studies: Good literature reviews provide a concise overview of the research on a topic.
They balance the need to be concise with the desire to provide deeper analysis. The choice of which articles are based on specific reasons.
For example: It does not matter how many cross-sectional observational studies are conducted looking at the correlation between self-efficacy and performance, this does not prove that one variable causes the other.
Before writing about causality consider whether X could cause Y, Y could cause X, or whether a third variables could cause both X and Y to covary.- to what extent is the measure valid, reliable, measuring something real), and (e) context of research (applied, laboratory, etc.- how ecologically valid is the task) (for more info see the Social Research Methods website).When describing research good literature reviews provide a quick snapshot of the important elements of the research and the important findings, while at the same time not wasting precious words that could be spent on other issues.Good literature review's “don’t lose the forest for the trees”.Common methodological limitations in I/O psychology include: (a) use of self-report measures (limits objectivity of conclusions); use of a observational designs (limits causal inference); (b) use of university samples (limits generalisability); (c) use of a common statistical analysis technique (e.g., most people researchers using mediation or SEM do not adequately consider alternative causal interpretations); and (d) use of experiments (may lack ecological validity).Describing an empirical study: When describing a study it is important to present only the important details.The limitations of a methodology can affect all studies that use the methodology.Understanding and critiquing the methodology allows the author to assess whether the theoretical claims argued by researchers using this methodology are justified and allows the reader to understand this also.Effect size can also be incorporated into a style of writing which puts relationships and effects in context.Using words like "small", "medium" and "large" to describe relationships in the literature, drawing on Cohen’s recommendations for effect size, can help the reader understand the relative importance of particular relationships (see Lee Becker's notes to learn more about effect sizes).