Which of the following is not one of the six major methods of data collection that are used by educational researchers?

Which of the following is not one of the six major methods of data collection that are used by educational researchers?
1). Observation
2). Interviews
3). Questionnaires
4). Checklists

Checklists : option 4 is the correct answer

• In an alloy, zinc and copper are in the ratio 1 : 2. In the second alloy, the same elements are in the ratio 2 : 3. If these two alloys be mixed to form a new alloy in which two elements are in the ratio 5:8, the ratio of these two alloys in the new allow
• Nidhi received simple interest off Rs. 1200 when invested Rs x at 6% p.a. and Rs y at 5% p.a. for 1 year. Had she invested Rs. x at 3% p.a. and Rs. y at 8% for that year, she would have received simple interest of Rs 1,260. Find the values Rs. x an y.
• A person ordered 4 shirts of brand A and some shirts of brand B. The price of one shirt of brand A was twice that of brand B. When the order was executed, it was found that the numbers of the two brands has been interchanged . This increased the bill by 4
• The letters A, B, C, D, E, F and G not necessarily in that order, stand for seven consecutive integers from 1 to 10, D is 3 less than A, B is the middle term. F is as much less than B as C is greater than D, G is greater than F.
• Direction: Read the following information carefully and answer the questions that follow: P, V, X, A, D, I, K and U set out for trip for different number of days such as 2, 8, 11, 5, 6, 4, 7 and 3, they go to the trip in the same order but the order of n