Embed Size (px)
Citation preview
First Find Your target
By George Head
Who am I?
• George Head• Sample Answers for 4 years • Experienced in Sampling data across the
world.
Agenda• Perfect World
• Niche Accurate Sampling
• Cost Efficiency Vs Being Representative
• Examples
• Conclusion
Perfect World
Everyone in the universe of your project has an equal
chance of getting selected
Therefore the probability is 1 in N
Mass Markets18 to 75 Living in Germany
Sample • RDD Sample (Random Digit dialling) • ER data (listed sample)• Online
Cost Efficiency
Being Representative
RDD
High
Low
Expensive Cheap
Dealing with a Niche
Bayern Munich
Sample • RDD Sample (Random Digit dialling) • ER data (listed sample)• Online
Cost Efficiency
Being Representative
RDD
Trying to find the Niche
Interested in football
Men / Women
Living in Munich
Cost Efficiency
Being Representative
Sampling
Try to find the Niche
Get a list of the Fans.
Bayern Munich Supporters club.
Everyone would qualify.
Cost Efficiency
Being Representative
Fans List
Cost Efficiency
Being Representative
VS
What's the survey all about?
Ticket prices?
“Yeah, they are a bit high”
Cost Efficiency
Being Representative
Sampling
Ticket prices?
Strip design?
What's the survey all about?
“Yeah I quite like it”
Fan List
“It’s a good look”
Cost Efficiency
Being Representative
Fans List
Strip design?
Consider this
Consider your problems.Consider the range of ways of achieving your goal.Consider the BIAS.
If your sample is bias then your results can be misleading and in some cases completely
wrong!
Real life examples
Brazilians in Rural England
Home Projectors
Large Lawns
iPhone
Good sampling MethodIdentify the problem
Who are you looking for?
What the method?
Objects of the survey. The BIAS.
Refine the sampling Approach.
Cost Efficient
Good sampling MethodIdentify the problem
Who are you looking for?
What the method?
Objects of the survey. The BIAS.
Refine the sampling Approach.
Cost Efficient
iPhone
Home Projectors
Large Lawns
High Income, Rural Areas, Luxury Product Ownership, interest in Gardening, Land Rover.
Conclusion
Tell the Sampler what the survey is about.
Consider your options
Remember the results of inaccurate sampling.
If your sample is bias then your results can be misleading and in some cases
completely wrong.
Questions
