unit-ix samples sampling measurement tools, instruments

Unit-IXSamples sampling measurement tools, instruments

Objectives:

• Define the term population sample and sampling.

• Identify and select various soft wares to calculate

sample size according to particular type of research.

• Discuss types of measurement tools for collecting data

from quantitative, qualitative and outcome research.

• Differentiate between interview guide and interview

schedule

Measurement tools

• Measurement tools are instruments used by researchers to aid in the assessment of participants.

• The instruments are used to measure or collect data on a variety of variables ranging from physical functioning to psychosocial wellbeing.

• Types of measurement tools include scales, interviews, structured questioner and informal observations.

Data collection

• Data collection is precise, systematic, gathering of information relevant to the research purpose or the specific objective, questions, or hypotheses of a study.

• Measurement is a research tool.• Scientific problem solving involves four steps

1. Developing the problem; 2. Formulating the hypotheses; 3. Gathering the data; 4. Analyzing and interpreting results.)

• Step 3 necessitates an understanding of measurement

Study variables are measured by a Variety of techniques

• Mail,

• Telephone,

• Face to face interviews

• Hospital records

• Self-administered

Before

writing

the q

uestio

ns, th

e

resear

cher m

ust de

cide w

hich o

f

these

method

s will

be use

d.

1. Sources of Data

2. Form of Data

3. Amount of Data

4. Accuracy/Reliability of Data

5. Design Fit

Major Issues of Data Collection

Sources of Data

Two broad categories:

1. Primary Data = information obtained

exclusively for current research

2. Secondary Data = archival or previously

recorded information

Advantages of Primary data Collection

• Based on researcher's need

• Control over measurement selection and

execution

Advantages of Secondary data collection

• Little cost or time required to access data

• Not confined to immediate level or unit of

analysis

Form of data

Self-Report Data• Subject provides account of attitude,

opinion, memory, personal characteristics, or circumstances

• Examples:• Surveys/Questionnaires• Interviews

Amount of Data

• Determine amount of data needed to conduct

study

• Data sources, time periods, and number of

participants (sample)

• Involves sampling techniques

Archival Data

• Previously collected data

• Examples:

• Prior research

• Procedural documents

The data related to a study focus can be collected from the

following means:

Questionnaire

Checklist

Interview

Observation

Records

Experimental Approach

Data Collection Tools

• Use validated questioner from of other research that similar topics

• Find out through literature review about similar topics

• Do not include questions those questions which you ‘just like to know’

Development of a Study Questionnaire

• Open-ended response

Allow subjects to answer the question, without any

restrictions imposed by the questionnaire's designer.

• Close-ended response Limits the answers which subject gives, requiring a

choice of one or more of the answers provided by the questionnaire.

Example: there has been a great deal of concern about the rising cost of food. How do you handle the problem of rising food cost?”

purchase cheaper types of foods Substitute other types of food in your diet Purchase large amounts of items which is on sale Eat at restaurants less Invite fewer people over to eat a meal at your house

ChecklistThese are items that comprise several questions on a topic and require the same response format.

Interview

Interview Guide

Interview Schedule

• A interview schedule is a interview with pre-coded question to produce quick and easy quantitative data which is high in reliability.

• A set of questions which are asked by interviewer and filled in on the given space in a face to face interaction with another person.

RecordsA record refers to all the numbers and statistics that institutions, organizations and people keep as a record of their activities.

Sources

1. Census data2. 2. Educational records3. 3. Hospital/clinic records

Experimental Approach A powerful design for testing hypothesis of causal

relationships among variables. Researcher controls the

independent variable & watches the effect on the

dependent variable.

Two Groups of Experimental Approach 1. Treatment / Experimental group

2. Control group

Thank you

?