Abstract: Systems and methods are disclosed enabling recommendations of content items available in multiple formats based on an expected difficulty of a user in comprehending individual formats of the content item. For example, a user wishing to increase reading fluency may be provided with a recommendation for a multi-format content item including both an e-book and an audiobook. The recommended multi-format content item may be selected such that the e-book is expected to be somewhat difficult for the user to comprehend, and such that the audiobook is expected to be relatively less difficult for the user to comprehend. Thereafter, the user may simultaneously consume multiple formats of the recommended content item (e.g., by listening to the audiobook simultaneously to reading the e-book) in order to increase reading fluency.

Abstract: A presentation analysis service may obtain presentation information from one or more computing devices that are presenting the item of content. The presentation information may be used to generate recommendations to be provided to a user that is consuming the item of content and/or to a provider of items of content. Further, the presentation information may be used to adapt a presentation of the item of content.

Abstract: Systems and methods are provided for causing aural and/or visual presentation of representative content in response to a request to progress or navigate through audio content at a scan rate exceeding a threshold playback rate. In some embodiments, a current position marker in the audio content may be repeatedly updated based on the scan rate. For each updated position of the current position marker, one or more characteristic words associated with the content near the current position marker may be determined. A continuous presentation of the determined characteristic words may be generated and presented aurally and/or visually in order to provide an indication as to the subject matter of the content at the current position.

Abstract: Improved curve plotting techniques are disclosed for drawing a substantially smooth curve in real time, from a plurality of sampled points, as the points are sampled, on a point-by-point basis. The curve is substantially smooth in that it has a continuously changing slope of G.sup.1 continuity, as opposed to a slope which changes in a discontinuous or stepwise manner. The curve plotting is performed by representing the x coordinates of the curve using a parametric equation x=?a.sub.x *(t.sup.2)!+?b.sub.x *t!+?c.sub.x !, and by representing the y coordinates of the curve using a second parametric equation y=?a.sub.y *(t.sup.2)!+?b.sub.y *t!+?c.sub.y !, wherein a.sub.x, a.sub.y, b.sub.x, b.sub.y, c.sub.x, and c.sub.y comprise six unknown quantities, and t is a "dummy" valuable. The derivatives of the parametric equations are employed to calculate and to plot the smooth curve.