In a survey to find the impact of Facebook usage on Students Academic achievement for example, respondents were asked about their Gender, Age Group, Ethnicity, Marital Status, No. of Hours spend on Facebook each week, and Grade Point Average.
Data collected from a respondent could be one of the following:
1. Gender: Male or Female
2. Age Group: 21 - 30, 31 - 40, 41 - 50, 50 and above
3. Ethnicity: Malay, Chinese, Indian, Others
4. Marital Status: Single, Married, Divorced, Widow/Widower
5. No. of Hours: 0 - 1 hr, 1 - 2 hrs, 2 - 3 hrs, 3 - 4 hrs, more than 4 hrs
6. Grade Point Average: 0.0 - 2.0, 2.0 - 2.5, 2.5 - 3.0, 3.0 - 3.5, 3.5 - 4.0
Can you see the difference between Data and Variable?
Variable:
In the above example, the variables used are:
Gender, Age Group, Ethnicity, Marital Status, No. of Hours, Grade Point Average
Definition of Variable:
A variable is an interested criterion to be measured or observed on each individual such as the variables mentioned above.
They are called variables because their values change from one respondent to another.
Quantitative and Qualitative Variable:
There are 2 types of variables, quantitative and qualitative.
Quantitative variables are variables which have numerical value such as No. of Hours and Grade Point Average.
... and there are 2 types of quantitative variables:
a) Discrete quantitative variables - are mostly integers or numbers used for counting e.g. number of children, number students etc
b) Continuous quantitative variables - are obtained through measuring process e.g. the height of a person, exam results etc
Qualitative variables are variables which have no numerical value such as gender, age group, marital status etc.
... and there are 2 types of qualitative variables:
a) Nominal - refers to the name of a category, cannot be measured or counted and cannot be arranged in sequence. Usually it is represented by a code number e.g Gender: "1" = Male, "2" = Female.
b) Ordinal - are non numerical but their categorical values can be arranged according to some ordered value e.g. ranking of satisfaction level or perception level, Likert scale of degree of agreement etc.
Exercise: 1.1
State whether each of the following variable is categorical or numerical type:
a. Weight of female students in a secondary school
b. Brands of national cars in Malaysia
c. Rate of crime in the Klang Valley
d. Colors of rainbow
Exercise: 1.2
Determine the following types of variables either discrete or continuous:
a. The waiting time of the customers in a bank
b. The price of 3G hand phones in the market
c. Rate of death in flood disaster
d. The number of students graduated from OUM
Exercise: 1.3
Classify the following observations whether the variables concerned are either Nominal or Ordinal types. For Ordinal type, please classify further to either Level Ordinal or Rank Ordinal:
a. Grade of final examination results of SBST1103 (A, B, C, D, E)
b. Level of achievement among probationers (Excellent, Very Good, Good, Satisfactory, Fail)
c. Types of public transportation available in Malaysia (Bus, Commuter Train, LRT, ERL)
d. The academic programs offered by OUM (Doctoral degree, Masters degree, Bachelors Degree, Diploma)
Here are the slides for Topic 1:
Kindly send your answers to richng8888@gmail.com stating your Name and Center.
