Evidence Based Practice & Research in Nursing University of Tabuk Faculty of Applied Medical Sciences Department of Nursing Evidence Based Practice & Research in Nursing Level 8, Academic Year (AY) 1434—1435 H Dr. Jay Qais Ablao

Population and Sampling Procedure

SAMPLING Selecting a given number of persons, objects or events called subset from a given population by a specified selection process (Cooper,2003).

Advantages of Sampling Makes possible the study of a large, heterogenous group For economy For speed Accuracy Saves the sources of data Department of Nursing

Disadvantages of Sampling If sampling is biased, or too small the conclusion may not be valid and reliable The respondents must have a common characteristics which is the basis of the study. If the population is very large and there are many sections and subsections, sampling procedure becomes very complicated. If the researcher lacks necessary skills and know how in sampling procedure, sampling may become biased Department of Nursing

Sloven Formula n= N 1+ Ne² where: n=number of samples N=population e=sampling error (1%-10%)

GENERAL TYPES OF SAMPLING PROBABILITY NON-PROBABILITY The sample is a proportion of the population and such sample is selected from the population by means of some way in which every element of the population has a chance of being included in the sample. The sample is not a proportion of the population and there is no system in selecting the sample. The selection depends upon the situation.

NON – PROBABILITY SAMPLING Accidental or Convenient Sampling Respondents are selected because of their convenient accessibility. Quota Sampling Sampling in which the researcher selects respondents according to some fixed quota. Purposive or Judgment Sampling Subjects are chosen because of their specific characteristics Snowball Sampling Respondents are chosen based on referral Department of Nursing

Non-Probability Advantages - Convenient - Economical Disadvantages - Biased samples - Some elements may have no chance to be included in the study

Department of Nursing Simple Random Sampling Randomly or by chance selecting sample from the population. Stratified Random Sampling Dividing the population into strata based from important categories relevant to the research interest. Cluster Sampling Used in natural grouping The entire population is divided into groups, or clusters, and a random sample of these clusters are selected. All observations in the selected clusters are included in the sample. - Researcher chooses every nth Sequential or Systematic Sampling Department of Nursing

Probability Advantages - Less bias - Every element has equal chance to be selected Disadvantages - Time consuming - Expensive - Inconvenient - Impossible to obtain

Curriculum & Course Development Committee References Sherman, R. O. & Eggenberger, T. (2008). Transitioning internationally recruited nurses into clinical settings. Journal of Continuing Education in Nursing, 39(12), 535-44. Tombaugh, J. Mayfield, C., & Durand, R. (2011). Spiritual expression at work: exploring the active voice of workplace spirituality. Retrieved from http://search.proquest.com/docview/868257687/1417EACB30831975A4A/1?accountid=33657 DEPARTMENT OF NURSING Curriculum & Course Development Committee Department of Nursing