SAMPLING & SURVEYINGTECHNIQUESRandom, Stratified, Systematic Sampling Methods

Survey Considerations

What is a sample and sampling?• A sample is a portion of the country’s population chosen

to represent specific information or data.

• Sampling is the process by which the sample size is selected.

• The sampling method depends on what the researcher wants to find out.

State a suitable hypothesis for his fieldwork. What is his sample size?

I am going to find out how many people living in Toa Payoh like to visit the library on weekends and the ages of the people who visit the library.My teacher said I need to get 50 surveys done. There should be quite a lot of people in Toa Payoh this Sunday. I think there should be at least 500 people.

Sampling Methods• There are three sampling methods which are commonly used.

• 1. Random• - any person is selected by random; not based on any criteria.• - similar to drawing numbers out from a box.• - computers can be used to create random number lists; e.g. interview every 1 st, 5th, 6th,

30th tourist who enters/exits the attraction.

• 2. Systematic- choosing the nth person that leaves the attraction where n is the regular number.- choosing the person who leaves Universal Studios after every 1 hour.- e.g. a group can choose to interview every 4 th person who exits from Universal

Studios.

• 3. Stratified• - people are divided up into different subsets (groups)• - the group may choose to interview only people of a specific income, age, gender,

dress, physical attributes etc.

Benefits of Each Method• Random Sampling• - simple to use• - equal opportunity of being chosen, no bias

• Systematic Sampling• - more uniform coverage of population compared to random• - simpler to use (just interview every 4 th person, do not need

to constantly check the random numbers)

• Stratified Sampling• - more precise data when sampling a specific subset/group

e.g. focus only on a specific age group or gender

Limitations of Each Method• Random Sampling• - time constraints as a large number needs to be surveyed for

accuracy• - population is not large enough or there are not enough areas to do

random sampling• Systematic Sampling• - it is more biased as not all members have an equal chance of

being selected.• - Repeatable patterns may result – e.g. when interviewing tourists,

every nth person that visits the attraction might be Japanese as the attraction was strongly promoted on a Japanese tourist site.

• Stratified Sampling• - difficult to identify people’s age and social background • - difficult to maintain complete accuracy of the information about the

subset.

Justify reasons for your choice of sampling

What sampling method should I

use??

Considerations before Surveying

When to survey• Tourism is seasonal. It is important to find out when is the

peak and off-peak season for tourism in the area before carrying out a survey.

• Special events may create a sudden surge in tourism e.g. free or discounted tickets into a theme park, new exhibits in an existing attraction i.e. River Safari / panda exhibit at Singapore Zoo.

• Tourist attractions have their own schedules e.g. Night Safari only opens at night.

Considerations before Surveying

Where to survey• Some parts of a tourist attraction may not attract the

target group. e.g. older or elderly may not frequent the rollercoaster attractions in a theme park.

• Some parts of a tourist attraction may not have many tourists passing by – e.g. a road junction in Chinatown will have more tourists passing through compared to a side-street.

• Unlikely to get enough samples, if you standing at the end of one way streets or dead-end roads.

Considerations before Surveying

How long to survey• Interviewers may become tired and fatigued if the survey

is carried out for a long time.

• Tourists visit attractions depending on their available time, schedule or interests. e.g. different groups of tourists may visit the Singapore Flyer in the day time or night time depending on which view they are interested in. If the interviewer only carries out interviews for the day time – they would not be able to get information from night-time visitors.