1. A user-interface method of selecting and presenting a collection of content items in which the presentation is ordered at least in part based on learned user preferences, the method comprising: providing a set of content items, each content item having at least one associated descriptive term to describe the content item; receiving input entered by a user for identifying desired content items; in response to the input entered by the user, presenting a subset of content items; receiving selection actions of selected content items of the subset from the user; learning preferred descriptive terms of the user by analyzing descriptive terms associated with the selected content items and by analyzing the date, day, and time of the selection actions and the descriptive terms associated with the selected content items to learn a periodicity of user selections of similar content items, wherein similarity of the similar content items is determined by comparing the descriptive terms associated with the selected content items with a previously selected content item, and wherein the periodicity indicates an amount of time between the selection actions of the similar content items relative to a reference point; associating the periodicity with the preferred descriptive terms associated with the similar content items; associating the preferred descriptive terms with the user; determining a measurement collection having measurements associated with the preferred descriptive terms, wherein the measurements represent relative preferences of the user for the preferred descriptive terms, wherein the measurement collection includes groups of the preferred descriptive terms, wherein the relative preferences of the user for the preferred descriptive terms in a particular group are treated as equal and the groups differentiate the relative preferences of the user for the preferred descriptive terms between the groups, and wherein a preferred descriptive term is included in the particular group at least in part based on at least one of (i) smoothing relatively smaller probability weights associated with less commonly expressed preferences of the relative preferences and (ii) aging preferences of the relative preferences of relative preferences captured in a relatively more distant past, and based further on bounding a range of values of the particular group using a relevance scale factor; and in response to receiving subsequent input entered by the user, selecting and ordering a collection of content items by promoting rankings of content items of the collection of content items associated with the preferred descriptive terms of the user according to differentiation provided by the measurement collection and further based on promoting rankings of those content items of the collection of content items associated with the preferred descriptive terms further associated with periodicities similar to the date, day, and time of the subsequent input; wherein at least one of the input and the subsequent input are entered by the user on an input constrained device.