NAME:SIBANDA MINENHLE
STUDENT NUMBER:N02127005C
SORS 2206 SURVEY METHODS
Assignment 1
A1.Target population is the entire group of people or objects to which the researcher wishes to
generalize the study findings and meet set of criteria of interest to researcher.A population is a
complete set of elements, persons or objects that possess some common characteristic defined by the
sampling criteria established by the researcher.Examples of target population include all people with
AIDS,all low birth weight infants,all school-age children with asthma .
Whereas Sample frame is a list of all the elements in the population from which the sample is
drawn.Frame is needed so that everyone in the population is identified so they will have an equal
opportunity for selection as a subject or element .Example includes a list of all school-age children with
asthma treated in pediatric asthma clinics in NUST.
b) Undercoverage errors occur when target population units are missed during frame construction, and
overcoverage errors occur when units are duplicated or enumerated in error.
c)Probability sampling every element (member) of the population has a probability greater than of being
selected for the sample,everyone in the population has equal opportunity for selection as a
subject.Whereas in Non probability sampling is a probability of convenience, Selection of the most
readily available people or objects for a study,no way to determine representativeness.
A2)Steps taken in questionnaire designing are,
Step 1: Decide what information is required
The starting point is for the researcher to refer to the proposal and brief and make a listing of all the
objectives and what information is required in order that they are achieved.
Step 2: Make a rough listing of the questions
A list is now made of all the questions that could go into the questionnaire. The aim at this stage is to be
as comprehensive as possible in the listing and not to worry about the phrasing of the questions.
Step 3: Refine the question phrasing
The questions must now be developed close to the point where they make sense and will generate the
right answers.
Step 4: Develop the response format
Every question needs a response. This could be a pre-coded list of answers or it could be open ended to
collect verbatim comments. Consideration of the responses is just as important as getting the questions
right. In fact, considering the answers will help get the questions right.
Step 5: Put the questionnaires into an appropriate sequence
The ordering of the questions is important as it brings logic and flow to the interview. Normally the
respondent is eased into the task with relatively straightforward questions while the more difficult or
sensitive ones are left until they are warmed up.
Step 6: Finalise the layout of the questionnaire
The questionnaire now needs to be fully formatted with clear instructions to the interviewer, including a
powerful introduction, routings and probes. There needs to be enough space to write in answers and
the response codes need to be well separated from each other so there is no danger of circling the
wrong one.
Step 7: Pretest and revise
The final step is to test the questionnaire. It usually isn’t necessary to carry out more than 10 to 20
interviews in a pilot because the aim is to make sure that it works, and not to obtain pilot results.
b)Qualities of a well designed questionnaire are ;
The length of questionnaire should be proper one.
The language used should be easy and simple.
The term used are explained properly.
The questions should be arranged in a proper way.
The questions should be in logical manner.
c) Characteristics of a good survey including: A clear understanding of the focus of the research and the
type of data that needs to be collected. A clear and consistent format. Clear and concise instructions
A3)Telephone interviews is an in-between methodology serving as the median between face to face
interviews and surveys.As a means of collecting primary ,qualitative data,telephone interviews deliver
high quality response with less timing and cost commitments of face to face interview. Advantages of
telephone interviews is that they are more cost effective and easier to conduct ,multiple points of view
can be gathered through multiple interviews. Disadvantages of telephone interviews are that
respondents have to actually answer the call and can hang up at any time,body language can not be
observed and we can not use any visual aids to assist in the interviewing .
b)Face to face interviews is a data collection method when the interviewer directly communicates with
the respondent in accordance with the prepared questionnaire.Face-to-face interviews help with more
accurate screening. The individual being interviewed is unable to provide false information during
screening questions such as gender, age, or race. It is possible to get around screening questions in
online and mobile surveys.Disadvantage is that it's a task to get a message across to a large amount of
people in one go. That personal touch that makes face-to-face communication so valuable isn't there,
and you can't guarantee that all of your audience are listening.
c)Self administered questionnaire is a questionnaire that is designed explicitly to be completed by a
respondent without an interviewer's assistance (or bias). Self-administered surveys are widely used for
collecting quantitative research.Advantage of the self-administered survey is the potential anonymity of
the respondent, which can lead to more truthful or valid responses. Also, the questionnaire can be filled
out at the convenience of the respondent. Since there is no interviewer, interviewer error or bias is
eliminated.Disadvantage is that without an in-person interviewer, respondents have no one to turn to if
they have a question, or if they need encouragement in order to complete the survey.
A4)Random population is a randomly selected subset of a population.
b)Ordered population
c)Periodic populationis a phenomenon where populations rise and fall over a predictable period of time.
d)Steps of selecting a systematic random sample are defining the population; choosing your sample
size; listing the population; assigning numbers to cases; calculating the sampling fraction; selecting the
first unit; and lastly selecting your sample.
A5)Stratified random sampling is a method of sampling that involves the division of a population into
smaller subgroups known as strata. In stratified random sampling, or stratification, the strata are formed
based on members' shared attributes or characteristics, such as income or educational attainment.
Stratified sampling can be used when your sample can be divided into mutually exclusive and
exhaustive subgroups that you believe will take on different mean values for the variable that you're
studying.Advantage of stratified random sampling is that it captures key population characteristics in the
sample and its disadvantage of stratified sampling is that the selection of appropriate strata for a sample
may be difficult.
A6)Cluster sample is a probability sample I which each sampling unit is a collection, group or cluster of
elements.
b)Cluster samples is advantageous in circumstances that , since cluster sampling selects only certain
groups from the entire population, the method requires fewer resources for the sampling process.Also
when the division of the entire population into homogenous groups increases the feasibility of the
sampling. Additionally, since each cluster represents the entire population, more subjects can be
included in the study.
A7)Similarities and differences between Cluster sampling and Stratified sampling are that ,
in cluster sampling are heterogeneous, so the individual characteristics in the cluster vary. In contrast,
groups created in stratified sampling are homogeneous, as units share characteristics.
Similarly, in cluster sampling you randomly select entire groups and include all units of each group in
your sample. However, in stratified sampling, you select some units of all groups and include them in
your sample. In this way, both methods can ensure that your sample is representative of the target
population.Both methods are examples of probability sampling methods, every member in the
population has an equal probability of being selected to be in the sample.
Both sampling methods divide a population into distinct groups either clusters or stratums,and
both methods tend to be quicker and more cost-effective ways of obtaining a sample from a population
compared to a simple random sample.