“Findings can be said to be internally invalid because they may have been affected by factors other than those thought to have caused them , or because the interpretation of the data by the researcher is not clearly supportable” (Seliger & Shohamy 1989, 95).
What can cause research to be invalid?
“Findings can be said to be internally invalid because they may have been affected by factors other than those thought to have caused them , or because the interpretation of the data by the researcher is not clearly supportable” (Seliger & Shohamy 1989, 95).
What makes a study legitimate?
For a study to be reliable the same experiment must be conducted under the same conditions to generate the same results . ... External validity is the process of examining the results and questioning whether there are any other possible causal relationships.
What does it mean When a researcher finds statistically significant results in a study?
Statistically significant findings indicate not only that the researchers’ results are unlikely the result of chance , but also that there is an effect or relationship between the variables being studied in the larger population.
How do you determine if a study is adequately powered?
Power is determined by 1) sample size (larger studies are inherently more powerful), 2) effect size (larger effects are easier to detect), 3) result variability (large standard errors/deviations blur the data), 4) the accepted α (being willing to accept lower levels of significance makes a difference more likely to be ...
What makes good internal validity?
Internal validity is the extent to which a study establishes a trustworthy cause-and-effect relationship between a treatment and an outcome . ... In short, you can only be confident that your study is internally valid if you can rule out alternative explanations for your findings.
What affects internal validity?
The validity of your experiment depends on your experimental design. What are threats to internal validity? There are eight threats to internal validity: history, maturation, instrumentation, testing, selection bias, regression to the mean, social interaction and attrition .
What makes a study reliable and valid?
The extent to which the results can be reproduced when the research is repeated under the same conditions. The extent to which the results really measure what they are supposed to measure. ... A valid measurement is generally reliable: if a test produces accurate results, they should be reproducible.
How do you know that your findings are correct?
So for your findings to be valid they must be accurate and appropriate , whilst referring to the question you originally aimed to answer. They must represent what you tested and they must be strong in the sense that the content validity is high; clearly showing that what you have tested represents your field of study.
What is the contribution to the body of knowledge?
Read things that make good contributions to the body of knowledge. The purpose of scientific research is to add to the body of knowledge. It is important that you understand what we mean by this term. The planned or hoped for contributions to the body of knowledge are usually found in the introduction to the report.
What does it mean when results are not statistically significant?
This means that the results are considered to be „statistically non-significant‟ if the analysis shows that differences as large as (or larger than) the observed difference would be expected to occur by chance more than one out of twenty times (p > 0.05).
How do you tell if a difference is statistically significant?
Determine your alpha level and look up the intersection of degrees of freedom and alpha in a statistics table. If the value is less than or equal to your calculated t-score , the result is statistically significant.
What does it mean when a test is statistically significant?
What is statistical significance ? “Statistical significance helps quantify whether a result is likely due to chance or to some factor of interest,” says Redman. When a finding is significant, it simply means you can feel confident that’s it real, not that you just got lucky (or unlucky) in choosing the sample.
What does a power of 80% mean?
For example, 80% power in a clinical trial means that the study has a 80% chance of ending up with a p value of less than 5% in a statistical test (i.e. a statistically significant treatment effect) if there really was an important difference (e.g. 10% versus 5% mortality) between treatments. ... See also p value.
What is power in quantitative research?
The power of a study, pβ, is the probability that the study will detect a predetermined difference in measurement between the two groups , if it truly exists, given a pre-set value of pα and a sample size, N.
What makes a study underpowered?
An underpowered study does not have a sufficiently large sample size to answer the research question of interest . An overpowered study has too large a sample size and wastes resources.
