Problems with Evaluating Text and Web Accessibility

sibility

In cases where the easy-to-read content is targeted at people with cogni- tive disabilities, accessible-content manuals mandate that the output text be evaluated by a focus groups of target users. In spite of the fact that these guidelines recommend the use of readability formulae for assessing the complexity of the final document, the European guidelines for writing easy- to-read documents state the following:

“To ensure that your document really meets the needs of your tar- get group and is suitable for their reading abilities, it is essential

that people with learning disability or groups of self-advocates read it before it is printed. This is the only way to ensure your publication really meets the needs and abilities of your target group, thus increasing the number of potential readers.(Freyhoff et al. 1998) ”

However, recruiting a focus group of people with cognitive disabilities is not straightforward. The main issues lie in the difficulty of recruiting enough participants with the required profile, the fact that this type of evaluation is particularly time-consuming, and the substantial funding required. Fur- thermore, not all people with cognitive disabilities have the same reading difficulties and even if access to such a group is secured, it is not feasible for the participants to evaluate lengthy documents (Brega et al. 2015). All of these barriers prevent the robust evaluation of the easy-to-read materials currently being produced and most developers of easy-to-read materials do not report any evaluation for the needs of people with cognitive disabilities. Another aspect of easy-to-read documents is the images used; however, this aspect has almost not been investigated. It is currently not known how exactly images affect comprehension and memorisation in people with different types of cognitive disabilities; various types of images are being used (both suitable and unsuitable) as there are no comprehensive guidelines regarding the image type; positioning of the image also varies widely, with most of the images being placed either on the left or the right hand-side of the paragraph; last but not least, little is known about the user preferences of the different groups of readers. As a result of this lack of clarity regarding the use

of images, there are no robust procedures for the evaluation of this component of the documents. This problem is discussed in more detail in Chapter 6, where we focus on the image component of the easy-to-read documents.

In addition to having to produce accessible text content, making the web accessible for people with cognitive disabilities entails investigation of a num- ber of design and interaction issues. There are almost no studies investigating the way people with autism interact with the web and there is a lack of un- derstanding about the way they process web pages, the way visual content affects their attention and, last but not least, what their user preferences are. To summarise, there are currently three main barriers to making text documents and the web pages accessible to individuals with autism:

1. The development and evaluation of accessible texts is time-consuming and costly.

2. There is lack of understanding of how the image component in easy-to- read documents affects text comprehension and memorisation among people with autism. Furthermore, there is no evidence to suggest which types of images (e.g. photographs, drawings, symbols) are most suit- able to be used.

3. There is a lack of understanding about the way people with autism interact with the web and about how to improve the web accessibility guidelines for this part of the population.

1.2

Goals

The goal of this thesis is to investigate new ways to evaluate and improve text and web accessibility for adults with autism.

This primary goal encompasses several secondary goals, which correspond to the research questions (RQs) outlined in the next section:

1. To evaluate automatically the accessibility of text content for readers with autism (RQ1, RQ2, RQ3)

The accessibility of text content is known as text readability. Read- ability has been defined as the ease of comprehension deriving from the style of writing (Harris & Hodges 1995) (Chapter 2). We will evalu- ate content readability at document level (Chapter 4) and sentence level (Chapter 5), through the training and evaluation of classifiers based on machine learning (ML) algorithms.

2. To investigate the effects of the presence of images and the types of images on text comprehension and memorisation among readers with autism (RQ4)

A number of accounts show that people with autism have a strong preference for processing visual over verbal information (Kana et al. 2006, Grandin 2009, Quill 1997, Dettmer et al. 2000). We will aim to find out whether their ability to process visual information could be used to compensate for their reading comprehension difficulties and to improve guidelines for writing easy-to-read material by investigating

the role of images in these documents.

3. To investigate the accessibility of web pages for those with autism (RQ5)

Since the Internet is nowadays one of the main sources of information, we will aim to ascertain whether those with autism encounter barri- ers when searching for information on the web and, if so, what these barriers are.