For example, intelligence is generally thought to be consistent across time. This means you're free to copy, share and adapt any parts (or all) of the text in the article, as long as you give appropriate credit and provide a link/reference to this page. When researchers measure a construct that they assume to be consistent across time, then the scores they obtain should also be consistent across time. Note, it can also be called inter-observer reliability when referring to observational research. The extent to which scores on a measure are not correlated with measures of variables that are conceptually distinct. Describe the kinds of evidence that would be relevant to assessing the reliability and validity of a particular measure. The scores from Time 1 and Time 2 can then be correlated in order to evaluate the test for stability over time. Test-retest reliability on separate days assesses the stability of a measurement procedure (i.e., reliability as stability). The extent to which a measurement method appears to measure the construct of interest. Criteria can also include other measures of the same construct. Or imagine that a researcher develops a new measure of physical risk taking. This refers to the degree to which different raters give consistent estimates of the same behavior. So people’s scores on a new measure of self-esteem should not be very highly correlated with their moods. In this case, the observers’ ratings of how many acts of aggression a particular child committed while playing with the Bobo doll should have been highly positively correlated. These are used to evaluate the research quality. Inter-rater reliability would also have been measured in Bandura’s Bobo doll study. In evaluating a measurement method, psychologists consider two general dimensions: reliability and validity. If the collected data shows the same results after being tested using various methods and sample groups, this indicates that the information is reliable. Search over 500 articles on psychology, science, and experiments. Instead, they conduct research to show that they work. For example, one would expect test anxiety scores to be negatively correlated with exam performance and course grades and positively correlated with general anxiety and with blood pressure during an exam. For example, if you were interested in measuring university students’ social skills, you could make video recordings of them as they interacted with another student whom they are meeting for the first time. Note that this is not how α is actually computed, but it is a correct way of interpreting the meaning of this statistic. Discriminant validity, on the other hand, is the extent to which scores on a measure are not correlated with measures of variables that are conceptually distinct. You can use it freely (with some kind of link), and we're also okay with people reprinting in publications like books, blogs, newsletters, course-material, papers, wikipedia and presentations (with clear attribution).eval(ez_write_tag([[728,90],'explorable_com-large-mobile-banner-1','ezslot_7',133,'0','0'])); Don't have time for it all now? Theories are developed from the research inferences when it proves to be highly reliable. Reliability refers to the consistency of a measure. In this method, the researcher performs a similar test over some time. It is a test which the researcher utilizes for measuring consistency in research results if the same examination is performed at … This involves splitting the items into two sets, such as the first and second halves of the items or the even- and odd-numbered items. Then you could have two or more observers watch the videos and rate each student’s level of social skills. For example, people’s scores on a new measure of test anxiety should be negatively correlated with their performance on an important school exam. The extent to which the scores from a measure represent the variable they are intended to. when the criterion is measured at some point in the future (after the construct has been measured). Here we consider three basic kinds: face validity, content validity, and criterion validity. In this case, it is not the participants’ literal answers to these questions that are of interest, but rather whether the pattern of the participants’ responses to a series of questions matches those of individuals who tend to suppress their aggression. Psychologists consider three types of consistency: over time (test-retest reliability), across items (internal consistency), and across different researchers (inter-rater reliability). Test-retest reliability involves re-running the study multiple times and checking the correlation between results. One approach is to look at a split-half correlation. ETS RM–18-01 Research Methods in Psychology by Paul C. Price, Rajiv Jhangiani, & I-Chant A. Chiang is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted. Typical methods to estimate test reliability in behavioural research are: test-retest reliability, alternative forms, split-halves, inter-rater reliability, and internal consistency. Retrieved Jan 01, 2021 from Explorable.com: https://explorable.com/test-retest-reliability. Split-half reliability is similar; half of the data are … The consistency of a measure on the same group of people at different times. The project is credible. They indicate how well a method, technique or test measures something. Before we can define reliability precisely we have to lay the groundwork. Interrater reliability is often assessed using Cronbach’s α when the judgments are quantitative or an analogous statistic called Cohen’s κ (the Greek letter kappa) when they are categorical. On the Rosenberg Self-Esteem Scale, people who agree that they are a person of worth should tend to agree that that they have a number of good qualities. Pearson’s r for these data is +.95. Test-retest. But how do researchers make this judgment? In its everyday sense, reliability is the “consistency” or “repeatability” of your measures. Reliability reflects consistency and replicability over time. Method of assessing internal consistency through splitting the items into two sets and examining the relationship between them. Validity is the extent to which the scores actually represent the variable they are intended to. But if it were found that people scored equally well on the exam regardless of their test anxiety scores, then this would cast doubt on the validity of the measure. Validity is a judgment based on various types of evidence. Take it with you wherever you go. Revised on June 26, 2020. Reliability has to do with the quality of measurement. Discussion: Think back to the last college exam you took and think of the exam as a psychological measure. Again, measurement involves assigning scores to individuals so that they represent some characteristic of the individuals. In a series of studies, they showed that people’s scores were positively correlated with their scores on a standardized academic achievement test, and that their scores were negatively correlated with their scores on a measure of dogmatism (which represents a tendency toward obedience). tive study is reliability, or the accuracy of an instrument. Reliability is about the consistency of a measure, and validity is about the accuracy of a measure. Like Explorable? The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) measures many personality characteristics and disorders by having people decide whether each of over 567 different statements applies to them—where many of the statements do not have any obvious relationship to the construct that they measure. For example, there are 252 ways to split a set of 10 items into two sets of five. You use it when data is collected by researchers assigning ratings, scores or categories to one or more variables. When the criterion is measured at the same time as the construct, criterion validity is referred to as concurrent validity; however, when the criterion is measured at some point in the future (after the construct has been measured), it is referred to as predictive validity (because scores on the measure have “predicted” a future outcome). The test-retest reliability method is one of the simplest ways of testing the stability and reliability of an instrument over time. Your clothes seem to be fitting more loosely, and several friends have asked if you have lost weight. This is as true for behavioural and physiological measures as for self-report measures. Compute Pearson’s. This will jeopardise the test-retest reliability and so the analysis that must be handled with caution.eval(ez_write_tag([[300,250],'explorable_com-banner-1','ezslot_0',124,'0','0'])); To give an element of quantification to the test-retest reliability, statistical tests factor this into the analysis and generate a number between zero and one, with 1 being a perfect correlation between the test and the retest. This is an extremely important point. We estimate test-retest reliability when we administer the same test to the same sample on two different occasions. In simple terms, research reliability is the degree to which research method produces stable and consistent results. In experiments, the question of reliability can be overcome by repeating the experiments again and again. This is typically done by graphing the data in a scatterplot and computing Pearson’s r. Figure 5.2 shows the correlation between two sets of scores of several university students on the Rosenberg Self-Esteem Scale, administered two times, a week apart. Clearly, a measure that produces highly inconsistent scores over time cannot be a very good measure of a construct that is supposed to be consistent. But how do researchers know that the scores actually represent the characteristic, especially when it is a construct like intelligence, self-esteem, depression, or working memory capacity? It is not the same as mood, which is how good or bad one happens to be feeling right now. Comment on its face and content validity. Then assess its internal consistency by making a scatterplot to show the split-half correlation (even- vs. odd-numbered items). Again, measurement involves assigning scores to individuals so that they represent some characteristic of the individuals. Although this measure would have extremely good test-retest reliability, it would have absolutely no validity. But how do researchers know that the scores actually represent the characteristic, especially when it is a construct like intelligence, self-esteem, depression, or working memory capacity? For these reasons, students facing retakes of exams can expect to face different questions and a slightly tougher standard of marking to compensate. For example, the items “I enjoy detective or mystery stories” and “The sight of blood doesn’t frighten me or make me sick” both measure the suppression of aggression. Cacioppo, J. T., & Petty, R. E. (1982). By this conceptual definition, a person has a positive attitude toward exercise to the extent that he or she thinks positive thoughts about exercising, feels good about exercising, and actually exercises. Assessing convergent validity requires collecting data using the measure. 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