- Published: September 27, 2022
- Updated: September 27, 2022
- Level: Doctor of Philosophy
- Language: English
- Downloads: 9
Research methods in criminal justice due: Introduction The term validity refers to whethera test, in fact, measures what is supposed to measure. Reliability can is defined as the measurement with exact precision. Triangulation is where different method of measurement is used for one item. Triangulation gives the same results on one concept.
Ways of determining the validity in research
Face validity as a measuring element is based on the researchers’ knowledge background and observation. The researcher relies on their intuition that what they are measuring is exactly what is required to be measured through a questionnaire.
Content validity emphases that each item has the capacity to determine what it is expected to measure. The researcher must support with an explanation each item on the questionnaire what it is expected to measure.
Pros and cons of face and criterion validity
Face validity can take items by face value and exactly assess the face value. Some items can have lower face validity than what it appears to have. It involves the assessment of normal people in the field. Content validity involves the assessment of experts in the field, but it is non-empirical and judgmental (Adler & Clark, 2014).
Reliability
Reliability is measured by test-retest which is obtained by running the same test twice on the same test subject in a given period. The results from both tests are evaluated for test of stability over that period. Example, a test done for a particular crime can be retested in the occurrence of another similar crime. The correlation will give a stability score.
Construct validity is assessment based on variables that are related. Construct validity carries weight when proof or of evidence is provided. Interrater reliability is used where results for one observer are strategically used in comparison with another using the same method. Interrater reliability is used when two or more measures are not reliable. They can compare correlatively those results using interrater (Maxifield & Babbie, 2012).
Scaling
A scale is defined as a measure of responding to a question, compilation of statements or questions used to respond to a concept studied. There are three types of attitudinal scaling used in criminal justice.
Thurstone scale uses paired comparisons and equal appearing intervals methods to scale. Judges are given several pairs of questions and choose which would most fit the concept of study. The one picked most becomes part of the questionnaire. The judges are required to give a number scale on the strength of each question. The researcher then takes the questions that showed the strongest agreement from the judges. The weak questions are eliminated when selecting the statements to use (Wainer & Braun, 2013).
Likert scale is a five to seven – point number scale from the strongly agreed to strongly disagreed. A total score is taken of all items in the scale. Those items that fall in between are eliminated. The middle number is undecided choice. Practically, numbers are determined according to personal taste or conviction. In Guttman scale, the cumulativeness of the scale is not perfect because an agreement with one item will respond to an agreement with another item (Bayens & Roberson, 2010).
Proposal scaling tool
Likert scale would be the most appropriate scale to use. Seven points scale will give interval data with minimal error and higher precision. The distances produced on the seven – point scale will not be equal but symmetrical.
Why Likert scale?
Likert scale is the summation of five or seven pint scale, seven giving the best results. Choices range from the least agreeable to strongly agreeable. All answers to questions are required to be given by the respondents. The researcher sums up the total items.
Analysis is done on the final results. It is important for choices to be numbered as they will give the researcher options on how to sort the results out. Example, numbers 1 to 7. 1 being strongly disagree, and seven strongly agree. Number 4 to be undecided (Dantzker & Hunter, 2012).
Conclusion
Validity and reliability may seem much the same, but they are different. Validity of data measurements through questions bring out its effectiveness. Reliability brings out the accuracy of measured data, and same results of the data re-measured. In questionnaire, inclusion of scaling type like Thurstone, Likert and Guttman is important. Likert being the most and popular method used measurement and assessment of data.
References
Adler, E., & Clark, R. (2014). An invitation to social research: How its done. Cengage
Learning.
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Bayens, G. J., & Roberson, C. (2010). Criminal justice research methods: Theory and practice.
CRC Press.
Dantzker, M. L., & Hunter, R. D. (2012). Research methods for criminology and criminal
justice. Sudbury, Mass: Jones & Bartlett Learning
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Maxfield, M. G., & Babbie, E. R. (2012). Basics of research methods for criminal justice and
criminology. Belmont, CA: Wadsworth/Cengage Learning
Wainer, H., & Braun, H. I. (Eds.). (2013). Test validity. Routledge
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