A comprehensive expert deposition in wage-and-hour sampling litigation covers six critical domains, each designed to expose a specific category of methodological vulnerability.
Population definition: Does the expert's population match the proposed class? Were individuals excluded who should have been included? Were seasonal or temporary workers improperly included or excluded? Population errors cascade through the entire analysis.
Sample selection: Was the sample truly random? Was the sampling frame complete? In one matter, the expert drew only from currently employed workers — excluding departed employees whose records might show different violation patterns. This selection bias inflated or deflated the violation rate depending on the direction of the bias.
Violation definition: What counts as a 'violation' in the expert's framework? In one analysis, the expert counted every meal period under 30 minutes as a violation — including 28-minute and 29-minute meals where the employee was fully relieved and chose to return early. The expert treated a 29-minute meal the same as a completely missed meal, inflating the violation count.
Paid premiums: Did the expert check whether meal period premiums were already paid for the flagged violations? If the employer paid the premium, the employee has been made whole on the wage component. The expert's violation count may include meals where premiums were paid, overstating damages.
Confidence intervals: A 45% violation rate with a 95% confidence interval of plus or minus 12 percentage points means the true rate could be anywhere from 33% to 57%. The expert's presentation may obscure this uncertainty.
Affirmative defenses: Does the methodology allow the defendant to present individualized defenses? Duran held that statistical methods 'cannot be used to bar the presentation of valid defenses.' (59 Cal.4th at p. 49.)