Page 1 : 9, TOOLS AND METHODS OF DATA COLLEC TION, , 290, Formula 9.3, , Where r= the correlation coefficient computed on the split-halves with Formula 9,2, , | = the estimated reliability of the entire test, d to estimate the internal consistency; howeve, , e The split-half technique is frequently use, i or coefficient alpha may be calculated by \, ‘SINg, , amore preferred method Cronbach’s alpha, the following formula (Formula 9.4):, , k Pas, Ti eae Notice,, aa oy, , Formula 9.4, Where r = the estimated reliability, k = the total number of items in the test., o?, = the variance of each individual items., oy? = the variance of the total test scores, >= the sum of, , e Egeevienss This aspect of reliability is. estimated-when a researcher is testing the reliability of a tool, which is used by two different observers to observe a single phenomenon, , simultaneously and independently or two presumably parallel instruments are administered to an individual at about the same time. For example, a rating scale is developed t, assess cleanliness of the bone marrow transplantation unit; this rating may be administered to observe the cleanliness of the bone marrow transplantation unit by two different, observers simultaneously but independently., , This is also known as interrater or interobserver reliability, which is estimated by the admiristration of tool to observe single event simultaneously and independently by two or more, trained observers. This reliability may be computed by using following equation:, , Number of agreements »«, , , , aa, Number of agreements + Number of disagreements, , PILOT STUDY, , * Innursing science research, the term pilot study is utilized in two different way®: It refers, to the so-called feasibility studies that are trial run or small-scale versions, which are done, in preparation for the major study. However, a pilot study can also be the ‘trying out’ of, pretesting of a specific research instrument., , e Apilot study is referred | to a small-scale preliminary tryout of the method to be used ina”, actually large study, which acquaints the researcher with problems that can be correct, in proportion for the large research study or is done to provide the researcher with a °F, portunity to try out the procedure, methods, and tools of data collection.