Data Collection Jacky Griffith/Anji Waring Faculty of Health and Social

Work

Methods of Data CollectionObjectives: To describe different methods of

data collection To discuss the strengths and

limitations of the different methods

Data CollectionExisting data

Already been generated by someone else. They are not creating the data themselve

New data Creating data that are new and not there bfore

Biophysiological testsLike

Height Weight BP

Ie from physiological data

Self report data What people say/tell/write. From interviews and questaire. Subjects have generated themselves Telling us things

Observation data Observations of the researcher What they see how they interprete Researcher led.

Data CollectionDimensions of quantitative data

Needs to be

Structured

Quantifiable

Need to turn it into numbers.

Objective Minimize bias No thoughts and feelings of researcher.

Biophysiologic and physical variables

In vivo – performed on or with people or living organismsIn life Open up to a number of potential extraneous data that make the results skewed.

In vitro (in glass) – data gathered and then subject to laboratory analysis◦ Gives absolute values◦ Tend to be accurate

◦ As long as the tools are accurate in the first place

◦ Easily standardisedTends to be used in randomised

trials – what a new drug does to someone. Does it work or is it just the same as doing nothing/or using another drug

Not used in surveys or qualitative work so much. Not looking for that type of material.

Looking at attitudes to weight

Self Report MethodsUsed in both qualitative and quantitative

Unstructured – qualitative approach

Structured - quantitative approach

Instrument: questionnaire or interview schedule

Research termilogy for the tool used.

May use tool such as GHQ general health questionaire, BDI beck depression inventory which are common to a lot of studies

May be used in a number of situation Have been already validated. Should always be referenced

May design new tool which needs validating

Needs to be tested to see if it is valid give you the results that can be applied to the area of interest.

The research should mention if they have invented or used old tools.

Need to road test an unvalidated tool.

Commones way Face validity Experts say that it does

what it purports to May design something specific

to this study eg survey questionnaire

Does not use scales

Can be done by interview with interviewer coding responses, questionnaire given out by researcher, by post

Writes down the answers in coded form.

Questionnaires/Scales Tools or instruments designed

to measure or explore specific issues or attitudes - not just a set of questions.

Need to go beyond and use question that will uncover things that are very specific

Types: Questions : - ◦ Closed questions◦ Yes/no ◦ A choice◦ Have to give an answer.◦ “ forced into an answer”◦ Open questions◦ Give your own answer and allow to

expand on what you really mean and give reasons.

◦ Say what you like, how you like. Response Categories:-

◦ Likert◦ 12345◦◦ Visual analogue◦ Yum –hmm-yuck

Questionnaire Design Aim:

◦ To measure what intend to measure

◦ Does what it says it does…..

◦ Validity – does it measure what it says it does

◦ External validity – generalisable to others

◦ Reliability – does it actually work

◦ To ensure respondent can complete the questionnaire.◦

Consider:◦ Wording◦ Are the words understandable for

the target sample?◦ Technical words◦ Level of language◦ Children/university graduates◦ Ambiguousness.

◦ DischargeCan it be interpreted in any other

way?You know what you mean, but

others may not understand…..

◦ information level required◦ descriptive – yes/no gives you

numbers◦ go beyond that with

scales/subsequent questions deeper level of information

◦ format of questions◦ nice and easy to get more difficult◦ hook them with something

interesting◦ need to know the demographics

◦ age◦ gender◦ educational level◦ job title

to make sense of the dataif you put that first, it can put

people off.

By the time you have gone through all the interesting stuff, then

people are more likely to fill the boring stuff as they finish

Leading questions They are let into something rather

than lead

◦ response categories◦ yes/no◦ choose from multiple choice◦ more than one choice◦ dichotomous choices◦ fixed choices

how are the responsing going to be managed

mix up positive and negative.

People re-write the questions

◦ length of questionnaire◦ people in pain…◦ time constraints

◦ method of administration◦ take away◦ face to face◦ sent◦ over the phone (almost like an

interview)

Strengths & LimitationsStrengths less costly

just print a lot don’t have to be there. But if you post it, it can be

dear Reach a lot of people

access large sample distance

allows a larger sample size anonymity

might be more willing to say what they feel with regard to what they want to say.

less threatening no power balance

discrepensies. data easy to analyse

Limitations response rate

can be quite low…. Need to put out more to get

suffient back Coverage

Can go back and ask “why”s No way of finding out where

attitudes originated. ability to complete

then these are excluded social desirability

people don’t want to admit, even if they are anonomous, that is not acceptable to the population as a whole.

Is saying what you think social acceptable

Is what they are saying ileagal? So they don’t want to even admit even if it is anonymous.

IInterviewsTypes:structuredsemi-structureddone in a very open way.

Not in the same oredeCan go backwards and forward

BoundriesCue questions “now can I ask you about…”

Unstructured In grounded theory Don’t know much about what you are studying.

Don’t have a schedule or cue questions.

“tell me about…..”No stearing at all

Could last one second or one millennium

Method face to facetelephone focus group

a group interviewconformity issues

Practical Considerations Design of interview schedule

What are the key areas that need to be covered?

Training of interviewers

If quantitive all be done in the same way

if qualitative:- beware of cultural difference and interpretive difference.

Place of interview Your teratory Their teratory

They have more power… Timing of interview

After the event … too soon, too far after.

20 mins to 90mins Recording the information

collected◦ Manually

◦ audiotape◦ videotape

Strengths & Limitations Strengths quick results clarification response rate additional information less superficial

Limitations practicalities expensive analysis bias social desirability Observation

What we see Actually observed rather

than what people say

When aim to describe what

happening in setting need overview of

activity/behaviour establish main issues as

prelude to further work.Overview

Leader on to something elseWhat are the main issues

Then look at something in more detail

Qualitative or quantitateive

Target Areas individual characteristics

non-verbal communication type of verbal communication behaviour

conformity

Types

Gold 1958

Covert Overt

Complete participation

Participant as observer

Complete observerUnethical

Used with babies and young children (but parents need to know

Participant as participantHawthorn effect

But if you are there long enough, people’s behaviour reverts

Practical considerations

Planning

◦ Structured (tick box) /unstructured (written down long hand)

◦ Field note can support other forms of data.

◦ what to sample◦ when to sample◦ how to record

◦ tool use (validated/unvalidated)

◦ recorded electronic◦ time available

Strengths and LimitationsStrengths first hand recording

you can see what is happening.

No self report bias

control over data collected

Limitations difficult to arrange observer bias only see what you want to see or expect to

see. time Hawthorne effect Training

Inter-rater reliability all interviews/observes are singing from the same song book.

Pilot StudiesFor new tools or doing

something new with an old toolTry it out first

Small scale version of the main study.

To smooth out future hiccups.

Try it out on similar types of group.

Some of the sample will do the pilot study.

Time & cost built into the proposal

May have to go back to basics and redesign the whole thing but it is better to find out now than after you have spent lots of money on the real thing. Carried out prior to main study

to:◦ test new methods ◦ check feasibility of design◦ ensure appropriateness of sample◦ identify potential pitfalls

DOES IT ACTUALLY WORK!!!!!!!!????!!!!

Modify aspects of main study according to results from pilot

Look to see how if there has been a pilot and does it work Did they need to change and how

Triangulation

Use of more than one method for collecting or interpreting data

Ie inteveiw as well as observation From surveyingFrom more than one set of data

Hoping that one will support the other

May show that there is a gap and may show if one or other is unreliable.Types: Methodological Theoretical Data Quantititve vs qualitative

Investigator2 people looking to see if they

find the same thing….To validate.