29 Surveys
Chandon, Morwitz, and Reinartz (2005) posits that “selfgenerated validity” can obscure the link between purchase intentions and purchase behavior. On average, the link between latent intentions and purchase behavior is 58% stronger among survey consumers that that of nonsurveyed consumers.
Sheppard, Hartwick, and Warshaw (1988) found that the link between intentions and behavior is about 0.53
A little more improvement can be achieved in predictive power if we use segmentation before forecasting sales based on historical purchases and purchase intention Morwitz and Schmittlein (1992)
Sampling  Interviews  Data environment  

1st era  area probability  facetoface  standalone 
2nd ear  random digital dial probability  telephone  standalone 
3rd era  nonprobability  computeradministered  linked 
Total survey error framework (Groves and Lyberg 2010)
Insight:
 Errors can come from bias or variance
 Total survey error = Measurement error + representation error
\[@Groves_2010, Fig. 3\]
Probability and Nonprobability Sampling
 Probability sample: every unit from a frame population has a known and nonzero probability of inclusion
 With weighting, we can recover bias in your sampling.
 Nonresponse problem
HorvitzThompson estimator (or bias estimator):
\[ \hat{\bar{y}} = \frac{\sum_{i \in s}y_i / \pi_i}{N} \]
where \(\pi_i\) = person i’s probability of inclusion (we have to estimate)
 Create a survey that leverages the power of people
Mass Collaboration

Human Computation: Train People > Train Lots of People > Train Machine
Cleaning
Debiasing
Combining

Open Call:
solutions are easier to check than generate
required specialized skills

Distributed Data Collection:
People go out and collect data
quality check
29.1 Anchoring Vignettes
Problem of interpersonal incomparability

Resources:

Help with 2 questions:
Different respondents understand the same question differently: Incomparaability in Survey Responses (“DIF”). Agreement on theoretical concept is almost nearly impossible.
How can we measure concepts that can only be defined by examples
Measure like usually, then subtract the incomparable portion. (i.e., using the assessment from the same respondents for a particular example/case to correct/adjust for the selfassessment).
Varying vignette assessments give us DIF (i.e., differential item functioning)
Since we created the anchors (i.e., examples), we know the true vignette assessments are fixed over respondents
29.1.1 Nonparametric method
Code the relative ranking of selfassessment in accordance to vignettes.
Inconsistencies would be considered ties.
Measurement Assumptions:
Response consistency: Each responder approaches the selfassessment and vignette categories in a same manner across questions.
Vignette Equivalence: For every vignette, the real level is the same for all respondents.
Used Ordered Probit to estimate.