Abstract: Video surveillance data is received from multiple disparate, unaffiliated locations at which various items are offered for sale. Based on the content of the video surveillance data, consumer preference behavior is characterized with respect to at least some of the items. The data is consolidated and can be made available for analysis.

Abstract: Adjustments to the amount of valve lift in an engine are readily made by corresponding adjustments to the location at which a cam actuated push rod contacts the push rod side of the valve actuating rocker arm. The invention provides an accurate and rapid means for adjusting the push rod contact position by slotting the push rod side of the rocker arm and fitting a square adjustment plate against a fixed index on top and bottom surfaces of the push rod side. Each adjustment plate has a hole for accommodating a tappet bolt and the holes are off-center located so that there is a different space between the hole and each of the square plates' four edges that may be rotated to a position against the fixed index to provide any one of four separate rocker arm ratios and therefore amounts of valve lift.