Analysis Dilemma: Check of Normality

I have data for three different groups- Treatment group and Comparison group is the treatment school and the comparison school itself. First I was confused whether I need to test the normality for individual groups or all the samples together.(??)

Later on I have run the analysis for all the samples together later on. (Kolmogorov-Smirnov test showed not significant results for individual groups, yet sample size is less than 30)

EXAM SCORE DATA:

In the Kolmogorov-Smirnov test the results are not significant for science and religion course before intervention and the maths score after intervention i.e. these data are normal. The scores for all other elements are significant which proves non-normality of the data. However, the skewness and kurtosis value for all the elements of the exam scores are within the acceptable range of normality that is -2 to 2 (George and Mallery 2010). The lowest value is -1.320 and highest is 0.873. The average skewness value is 0.316 and the kurtosis value is -0.438. So the exam scores data are within the acceptable range of normal distribution. The histograms look good, though not good for few of them.

QUESTIONNAIRE SURVEY DATA:

Kolmororov-Smirnov test yielded significant results for all of the elements in the questionnaire which means the data are not normal. Yet this test can be conservative for some of the cases. However the average value for the skewness and kurtosis is -0.599 and -0.577 which is within the acceptable range of the normal distribution which is -2 to 2 (George and Mallery 2010). The histograms don’t look good for all of them but not bad also. The histogram looks good for most of them.

So what shall I consider?- the test of normality? Or the skewness and kurtosis value?

I was looking for solutions as I learnt from Field, Andy (2000) about the strength of parametric statistics over non-parametric ones. My concern is we might miss a significant effect in non-parametric analysis which might actually exist there (proved in Parametric tests). "If there is a genuine effect in the data then a parametric test is more likely to detect it."(Field, Andy 2000, p 49)

Comments

Planning breaks during your PhD

When I started my PhD here people told everything about work during the PhD like working long hours or even during week end, working hard during the Government Holidays when even the school office is closed and access is limited to the University... bla bla. The thing that I never heard of is planning a break during this long journey. So I took it for granted that I am married to the PhD for this three years and should not think of anything else. But soon I became tired, started nagging with my husband for holidays and at one time I freaked out. It was just after three months during Christmas. Me and my husband were not really used to the idea of planning the breaks long before and found it impossible to go somewhere as the ticket prices were untouchable at the moment. So I got rotten at home for those few days of vacation. I carried loads of books to home which remained untouched until the day when the school reopened. I am from a country where people generally don't plan

Patha Bhavana, Shantiniketan_ More than 100 years of outdoor learning practice

Patha Bhavana ( Bengali : পাঠ ভবন ) is an institution of primary and secondary education in Santiniketan , West Bengal , India . It was founded by Nobel laureate Poet Rabindranath Tagore in 1901 with only five students which later grew into Visva-Bharati University . The school is established based on the philosophy of learning being in nature with close connection to it without any superficial barriers between teachers and students. It was opposed to the mainstream classroom learning system based on the books only. It’s often referred to as an ashram system where the teacher is guru and teaches his or her disciples sitting in the shade of a tree. It is one of the two primary and secondary school affiliated with the Visva-Bharati University; the other being Shiksha Satra . Patha Bbhavana is established for children from class I to class XII. Generally in the schools in Indian subcontinent children remain in the classrooms. The teacher moves from one

Review: Outdoor Environmental Education Research Seminar 2016

I attended the Outdoor Environmental Education Research Seminar 2016 at Broomlee Outdoor Education Centre from 13-15 April 2016 organized by the PhD students based in Moray House School of Education, the University of Edinburgh. Different people have different interests and they pick different things from a seminar or talk. This is my account of what I learnt from the Seminar which might not be the same as other participants. However, I enjoyed these three days to the fullest and would like the conversation to be continued. Based on my perceptions I grouped my learnings under several headings- impact of outdoor environment, teachers' perceptions, research methods, learning for sustainability, policy impact, publishing research and outdoor activities. Figure 1 : I enjoyed the food in Broomlee Outdoor Education Centre- they kept in mind individual choices and preferences Impact of outdoor environment- Matluba Khan, Aristea Kyrikou, Jamie Hamilton Me and Jamie explore

PhD_the other half

Search This Blog