Rating-based collaborative filtering is the process of predicting how a user would rate a given item from other user ratings. We propose three related slope one schemes with predictors of the form f (x) = x + b, which precompute the average difference between the ratings of one item and another for users who rated both. Slope one algorithms are easy to implement, efficient to query, reasonably ...

In [k] = [k]×[k]× · · · ×[k], a coordinate line consists of the collection of points where all but one coordinate is fixed and the unfixed coordinate varies over all possibilities. We consider the problem of marking (or designating) one point on each line in [k] so that each point in [k] is marked either a or b times, for some fixed a or b. This is equivalent to forming a strategy for a hat gue...

Nowadays, item-based Collaborative Filtering (CF) has been widely used as an effective way to help people cope with information overload. It computes the item-item similarities/differentials and then selects the most similar items for prediction. A weakness of current typical itembased CF approaches is that all users have the same weight in computing the item relationships. In order to improve ...

Item banks are typically constructed from responses to items that are presented in one fixed order; therefore, order effects between subsequent items may violate the independence assumption. We investigated the effect of item order on item bank construction, item calibration, and ability estimation. 15 polytomous items similar to items used in a pilot version of a computer adaptive test for anx...

In order to improve the precision of rating prediction for personalized recommendation online, an approach incorporating personalized contextual information in item-based collaborative filtering is proposed. In this paper we analyze how to learn personalized contextual information and predict ratings for unknown items based on the well-known SlopeOne itembased collaborative filtering. Finally, ...

in this paper the factor of safety (fs) and critical line-segments slip surface obtained by the alternating variable local gradient (avlg) optimization method was presented as a new topic in 2d. results revealed that the percentage of reduction in the fs obtained by switching from a circular shape to line segments was higher with the avlg method than other methods. the 2d-avlg optimization meth...