There are several alternative response formats available to the Web survey designer. These include radio button, check boxes, drop boxes and text fields. The choice of these HTML form elements is often made with little consideration of measurement error, but rather for reasons of efficiency or space. In this paper we explore three common forms of presenting response options to a single choice question. Specifically, we examine a series of radio buttons, a drop box with none of the items initially displayed until the respondent clicks on the box, and a scrollable drop box with five of the ten options initially visible, requiring the respondent to scroll to see the remainder of the items. In addition we reversed the order of the response options for half of the sample, yielding a 3*2 experimental design. This experiment was embedded in a survey administered to a sample from an online panel administered by Survey Sampling, Inc., yielding over 2,500 respondents, with random assignment to the six conditions. We explore the effect of order and format on the responses obtained to two different questions, one on breakfast cereal nutrients and the other on desirable automobile features. We discuss the implications of our findings both for Web survey design and for the literature on response effects and satisficing. We generally find support for the primacy effects found in the literature on visually-presented items, but also find some surprises in terms of the effect of format and in terms of the time taken to complete the items.