We present results from using Probit models to classify and rank texts of varying complexity from multiple sources. We use multiple linguistic sources including Swedish easy-to-read books and investigate data augmentation and feature regularisation as optimisation methods for text complexity assessment. Multi-Scale and Single Scale Probit models are implemented using different ratios of training data, and then compared. Overall, the findings suggest that the Multi-Scale Probit model is an effective method for classifying text complexity and ranking new texts and could be used to improve the performance on small datasets as well as normalize datasets labelled using different scales.

Data driven approaches to readability analysis for languages other than English has been plagued by a scarcity of suitable corpora. Often, relevant corpora consist only of easy-to-read texts with no rank information or empirical readability scores, making only binary approaches, such as classification, applicable. We propose a Bayesian, latent variable, approach to get the most out of these kinds of corpora. In this paper we present results on using such a model for readability ranking. The model is evaluated on a preliminary corpus of ranked student texts with encouraging results. We also assess the model by showing that it performs readability classification on par with a state of the art classifier while at the same being transparent enough to allow more sophisticated interpretations.