Harvest

Collecting data for a field investigation

FETP India

Competency to be gained from this lecture

Collect data for a field investigation according to standard operating

procedures

Key issues

• Data quality• Field work

Data quality

• Reliability Reproducibility/repeatability/precision Ability of a measurement to give the same

result or similar result with repeated measurements of the same thing

Refers to stability or consistency of information

• Accuracy• Ability of a measurement to be correct on the

averageData quality

ReliableAccurate

Not reliableAccurate

ReliableNot accurate

Not reliableNot accurate

Reliability and accuracy

Data quality

Seven steps to data collection

1. Draft question-by-question guide2. Train staff members who will collect data3. Standardize the data collection

procedure4. Initiate field work5. Control instruments6. Debrief to trouble shoot difficulties7. Validate

Data collection

1. The question by question guide(q-by-q)

• Short document to be understood as a guide for field workers

• Consider each question, number by number

• Provide guidance as to how the data should be collected

• Used as a road map for good data collection Drafted initially Revised as issues arise and are addressed

Data collection

Example of q-by-q

• Question 6 (Housing): Observe the house and note if made of

mud or bricks

• Question 12 (Household income) : Identify all the person with financial

income in the household Estimate each source of income Sum up to generate household income

Data collection

2. Train field workers

• Select good, experienced field workers• Present the study and its objectives

Slide presentation

• Distribute the q-by-q• Walk people through the q-by-q• List tasks to be conducted • Answer questions• Simulate interviews within the team

Data collection

3. Standardize data collection

• Interviewers Take field workers by teams in the field Conduct interviews as a small group Note issues that may come us, resolve

them as a group Continue until the procedure is clear to

everyone

• Instruments Calibration, standardization

Data collection

4. Field work

• Send field workers by team of at least two persons Interviewer (Speak the local language) Note taker

• Initiate data collection• Be available to answer questions• Visit teams in the field• Do not press for quick completion

Data collection

5. Checking the instruments

• Each team checks the instrument before leaving the household Cross check: The one who did not fill checks

• The supervisor checks the instruments before leaving the location

• All take responsibility for the instrument: Names and signatures

• Investigator checks instruments as they come

Data collection

Checks to conduct

• Completeness Did the field worker fill all items?

• Readability Is the writing readable?

• Consistency Do the answer make sense? Is there internal consistency?

Data collection

Auto-coding

• Q.25: Where did you go when your child had diarrhoea? 1. Hospital2. Public clinic3. Private clinic4. Pharmacist

2

Data collection in the field

Coding right after field work

Data collection

6. Debrief to trouble shoot difficulties

• Regular meetings Evening or morning

• Facilitate a discussion about Issues identified Clarification needed

• Make note of decisions on the q-by-q if needed

Data collection

7. Validate

• Select a number of study participants at random

• Conduct a second interview • Compare results• Debrief discrepancies with:

Field worker if individual issue Group if general issue

Data collection

Take home messages

• Understand the concepts of data quality• Supportive supervision and team work

are key to good quality data collection