APPLICATION OF MEAN IN NURSING RESEARCH
Measures ofcentral tendency are the descriptive statistics used in quantitativeanalysis of data by providing simple summaries about the data andscores. A typical score is likely to found in the middle ofdistribution while the other scores are clustered around it. Measuresof central tendency provide a value around which scores in a studycluster (Oermann & Gaberson, 2014). There are three commonmeasures of central tendency applied for the interpretation of testscores. They are the mode, median, and mean. Mode refers to thevalue in a distribution of scores that has the highest frequency. Itis the simplest measure of central tendency and can be easilyidentified from a distribution since it does not need mathematicalcalculation. The mode has the lowest stability among the three sinceit tends to fluctuate considerably from one sample to the other.
Walker &Maddan (2013) describe median as the point which divides distributionof scores into equal halves. It is a representation of the 50thpercentile. Since median is not influenced by the value of eachscore, it is a good indication of a typical score. Oermann &Gaberson (2014) refer the mean as the average of all values in atest. It is calculated through the division of the sum of all valuesby the total number of scores. Therefore, every score in adistribution influences the value of the mean. This characteristicmakes it the most preferred index of central tendency when a measureof the total distribution if required. However, the mean may notreflect the typical score because it is sensitive to the effects ofextremely high or low scores. Most studies employ mean to describedata. This paper focuses on how Eswi, Radi & Youssri (2013)applied mean in their study.
Description of the study
Eswi, Radi &Youssri (2013) carried out a study to investigate perceptions aboutstress and stressors. Stress is one of the major health problems inthis modern world. It results from a complex and dynamic interactionsbetween individuals and their environments. Stressors are thesituations or events that have the potential to influence the healthof a person. They cause stress. Eswi, Radi & Youssri (2013)noticed the increasing cases of stress in medical traininginstitutions. One of the indicators they used to evaluate thiscondition is the symptoms of depression among the students. Thefactors that are associated with stress among medical undergraduatesinclude academic pressure, social issues and financial problems.
In their study,Eswi, Radi & Youssri (2013) utilized a descriptive,cross-sectional research designed. They conducted the study in KingSaud Bin Abdul-Aziz University of Health Science in Jeddah. 100participants were selected to take part in the study. Theinvestigators structured questionnaire to collect data aboutperceived stress and stressors among the students. Data collectiontools used in the investigation include the perceived stress scale(PSS) and the Inventory of College Students’ Recent LifeExperiences (ICSRLE). The study findings indicated that the studentsusually feel nervous or stressed. The students were upset about thestressors that were beyond their control. Sudden events or conditionswere found to be among the causes of stress among the undergraduates.The common source of stress was the responsibilities they had. Theinvestigators found a significant correlation between stress and lifeexperiences. Eswi, Radi & Youssri (2013) recommended educatingthe student how they can manage stress.
How mean was used in the study
The investigatorsused the mean in various areas of their research. Eswi, Radi &Youssri (2013) used this measure of central tendency to describe thecharacteristics of their sample. The mean age of the participants was22.5 years. They arrived at 22.5 years by adding all the ages of theparticipants and then dividing by 100 (number of participants). Theyalso used mean to describe the overall response they received afteradministering the questionnaires. The mean of the responses wascalculated for every question or statement in the questionnaire. Thereaction to the questionnaire is used in determining the reliabilityof the data collected. When the response is low, the data will beless reliable. The mean of responses indicated the appropriateness ofthe content of the questionnaires.
The mean was alsoused to describe the results of the perceived stress and lifeexperiences. The average score of perceived stress of the studentsbased on the PSS was 23.3. The students indicated that they had highlevels of life experiences that cause stress. This outcome was shownby the mean value of the recent experiences which was found to be114.2. Eswi, Radi & Youssri (2013) also employed the measure ofcentral tendency to compare the results of their study (perceivedstress) with the findings of other studies. The mean (23.3) ofperceived stress in their study was lower than the mean (30.84) forundergraduates in a Pakistani medical college.
Appropriateness of using the mean in the study
As mentionedearlier, this measure of central tendency provides the average valuesof scores stress and stressors. The mean was used to bring out thepicture of stress and stressors of all students. The 100 participantshad different scores of perceived stress. Therefore, the presentationof the scores in their crude form could have complicated theiranalysis. Since Eswi, Radi & Youssri (2013) aimed at studying allstudents instead of one, it was necessary to use a measure thatrepresents all the students. The score of every participantinfluenced the mean of all scores of stressors and stress. Thisproperty makes this measure of central tendency a representative ofperceived stress and stressors among the undergraduates. Since theparticipants were selected randomly, the results of the study alsorepresented the extent of stress in all the students of the King SaudBin Abdul-Aziz University of Health Science. The appropriateness ofthe mean in presenting the data is reduced since there are caseswhere a student may have too high or low scores of perceived stressand stressors. Therefore, this measure of central tendency was notable to represent all the students in some way.
How investigators addressed the assumptions of central tendency
The assumptionthat the mean is a good representative of symmetric data for theperceive stress and stressors was adequately dealt with in the study.Eswi, Radi & Youssri (2013) used normality test and measures ofvariability. Normality test was used by comparing the scores of theparticipants with a normally distributed set of values which had thesame mean and standard deviation (Ghasemi A. & Zahediasi, 2012).The sample passed the normality test given its small size. Measuresof variation describe how scores deviate from the mean. Eswi, Radi &Youssri (2013) used standard deviation. The investigators providedstandard deviation for every mean. This approach was appropriatesince it enables individuals to figure out the representativeness ofthe mean. In most cases, the standard deviation was around 1.00. Thisshows a small deviation of the scores from the mean. Therefore, themeasure of central tendency was a fair representation of the scoresfor perceived stressors and stressors.
Level of measurement of variables
PSS was a scaleof measurement for perceived stress. It is a standard psychologicaltool for determining the stress in an individual’s life. Itmeasures the extent to which conditions in a person’s life areappraised as stressful. PSS is a technique designed to capture howunpredictable, uncontrollable and overloaded the students found theirlives. The appropriateness of this level of measurement is supportedby the fact that it contains general questions and thus, does nothave any content specific to any subpopulation in the sample. Thestudy examined the stress and stressors that are common to all thestudents. Therefore, the generality of the PSS questions wasappropriate.
Another level ofmeasurement the investigators used to study perceived stress andstressors is the ICSRLE. The scale consists of 49 elements that showthe extent of an individual’s life experiences within a period ofone month. The ICSRLE was appropriate for this study since it enabledthe investigators to determine life experiences that are responsiblefor the stress among the students. However, the participant mighthave found it difficult to determine the degree of the situations. Asa result, the data collected have some chances of being inaccurate.The inaccuracy of the data affects analysis and interpretation. Thestudy may report what is slightly different from the actualperception of stresses and stressors among the students.
Presentation of data
The investigatorsmainly used tables to present the data collected and analyzed duringthe study. The sample characteristics were presented in tabular form.The tabular approach enabled the researchers to explore all thefeatures of the sample in terms of number and proportion. The resultsof perceived stress and life experiences were also displayed usingtables. This approach was appropriate since it enabled thepresentation of some aspects that could not be accommodated in othermethods of data presentation (Swires-Hennessy, 2014). However, thelimitation of tables in presenting large data sets is that a personmay find it difficult to read through the lines and compare variousvariables. Also, it does not have a good visual impression. Eswi,Radi & Youssri (2013) also described the results in paragraphs.This enabled the presentation of results which requirementexplanation and could not be presented using tables or graphs.
Measures ofcentral tendency include mean, mode and median. The mean is the mostpreferred among the three due to its high degree ofrepresentativeness. The mean is calculated using the values of allthe participants in the sample. This measure of central tendency wasused to describe various variables in the study. Extreme scoresaffect the representativeness of mean. However, the investigatorsaddressed this issue using the normality test and measures ofvariation. The levels of measurement, the PSS and ICSRLE, used wereappropriate for the study since they enabled the investigators tomeasure the study variables. The tables used to display data suitedthe investigation.
Eswi, A. S., Radi, S., & Youssri, H. (2013). Stress/stressors asperceived by baccalaureate Saudi nursing students. Middle-EastJournal of Scientific Research, 14(2), 193-202.
Ghasemi, A., & Zahediasl, S. (2012). Normality tests forstatistical analysis: a guide for non-statisticians. Internationaljournal of endocrinology and metabolism, 10(2),486-489.
Oermann, M. H., & Gaberson, K. B. (2014). Evaluation andtesting in nursing education. Springer Publishing Company
Swires-Hennessy, E. (2014). Presenting data: How tocommunicate your message effectively. Wiley
Walker, J. T., & Maddan, S. (2013). Statistics incriminology and criminal justice: Analysis and interpretation.Burlington, Mass: Jones & Bartlett Learning.