What makes something reliable

If the new measure of self-esteem were highly correlated with a measure of mood, it could be argued that the new measure is not really measuring self-esteem; it is measuring mood instead. All these low correlations provide evidence that the measure is reflecting a conceptually distinct construct. Method of assessing internal consistency through splitting the items into two sets and examining the relationship between them.

In reference to criterion validity, variables that one would expect to be correlated with the measure. The extent to which scores on a measure are not correlated with measures of variables that are conceptually distinct. Skip to content Chapter 5: Psychological Measurement.

Define reliability, including the different types and how they are assessed. Define validity, including the different types and how they are assessed. Describe the kinds of evidence that would be relevant to assessing the reliability and validity of a particular measure.

Psychological researchers do not simply assume that their measures work. Instead, they conduct research to show that they work. If they cannot show that they work, they stop using them. There are two distinct criteria by which researchers evaluate their measures: reliability and validity.

Reliability is consistency across time test-retest reliability , across items internal consistency , and across researchers interrater reliability. Validity is the extent to which the scores actually represent the variable they are intended to.

Validity is a judgment based on various types of evidence. The reliability and validity of a measure is not established by any single study but by the pattern of results across multiple studies. The assessment of reliability and validity is an ongoing process. Then assess its internal consistency by making a scatterplot to show the split-half correlation even- vs.

Discussion: Think back to the last college exam you took and think of the exam as a psychological measure. What construct do you think it was intended to measure? Comment on its face and content validity. What data could you collect to assess its reliability and criterion validity? Cacioppo, J. The need for cognition. Journal of Personality and Social Psychology, 42 , — Likewise, Web postings with a.

Web postings with the. Database postings which publish entries from encyclopedias or articles are also trustworthy, even if no author is listed. Encyclopedias edit and update entries, citing sources and using reliable authors. As a reader, you must be careful about what you consult as a reliable source of information. That a source is in print or posted on the Web does not automatically make it trustworthy.

You can always find information on any source. As a critical reader, you deserve the best, the most current, and the most reliable. Be sure to screen what you find to make sure that it is reliable. Not reliable! The brochure wants readers to buy new cars. While features of each model will appear, they may not be complete, nor will they reflect objective tests of the products. While this brochure is probably less emotionally biased than a television infomercial, it's purpose is the same: to sell the product and to persuade readers or viewers to buy.

A Web page describing one individual's negative experience at a popular resort. While such a negative report should encourage readers to seek other, more comprehensive information about the resort, one person's experience does not necessarily reflect a general trend.

Do I have access to this journal? How do I request materials using Interlibrary Loan? How do I pay fines? How do I access resources from off-campus?

How do I know if my articles are scholarly peer-reviewed? Short, simple how-to and demos of frequently asked questions about using the Libraries and information resources. Frameworks There are certain frameworks that information professionals have put together to help people think critically about the information provided.

The questions are: Who is the author? Authority What is the purpose of the content? Accuracy Where is the content from? Publisher Why does the source exist? Purpose and Objectivity How does this source compare to others? The criteria are: Source: Who or what is the source?

Motive: Why do they say what they do? Authority: Who wrote the story? The reliability and validity of your results depends on creating a strong research design , choosing appropriate methods and samples, and conducting the research carefully and consistently.

Validity should be considered in the very earliest stages of your research, when you decide how you will collect your data. Ensure that your method and measurement technique are high quality and targeted to measure exactly what you want to know. They should be thoroughly researched and based on existing knowledge. For example, to collect data on a personality trait, you could use a standardized questionnaire that is considered reliable and valid.

If you develop your own questionnaire, it should be based on established theory or findings of previous studies, and the questions should be carefully and precisely worded. To produce valid generalizable results, clearly define the population you are researching e. Ensure that you have enough participants and that they are representative of the population.

Reliability should be considered throughout the data collection process. Plan your method carefully to make sure you carry out the same steps in the same way for each measurement. This is especially important if multiple researchers are involved. For example, if you are conducting interviews or observations, clearly define how specific behaviours or responses will be counted, and make sure questions are phrased the same way each time. When you collect your data, keep the circumstances as consistent as possible to reduce the influence of external factors that might create variation in the results.

For example, in an experimental setup, make sure all participants are given the same information and tested under the same conditions.

Showing that you have taken them into account in planning your research and interpreting the results makes your work more credible and trustworthy. Have a language expert improve your writing. Check your paper for plagiarism in 10 minutes.

Do the check. Generate your APA citations for free! APA Citation Generator. Reliability vs validity Reliability Validity What does it tell you? 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. How is it assessed? By checking the consistency of results across time, across different observers, and across parts of the test itself.