Ensuring Accessibility: Writing Alt Text
A picture is worth a thousand words, but what if you can’t see the picture? We are in the process of writing alternative text captions, or alt text, for the thousands of objects in our collections. Here we share an insight into how and why we are writing these captions – and the challenges of writing alt text for some of our collection objects.
What is alt text?
Alt text gives a written description of the images used in a webpage. It is primarily used by screen reader software, which reads web pages aloud to enhance the accessibility of online content for users. Including alt text for our images allows everyone to engage with and enjoy Parliament’s Heritage Collections.
How we write alt text
So how do you describe an image? It can be harder than it sounds!
Firstly, many popular screen readers stop reading alt text captions after the first 125 characters, asking the user if they’ve heard enough or if they want to hear the caption in full. This means it’s important to summarise the image clearly and succinctly to start with, before diving into greater detail. For many objects in our collections, there can be a lot of different things happening all in one image, so we try to focus on the primary subject first and expand from there.
How would you describe this image?
The alt text we have written is:
Watercolour drawing depicting two men on a wooden platform amongst the ruins of a building. The two small figures are in the foreground. One is standing looking directly out to the viewer while the other sits with his back slightly turned, looking at the ruins below. They are wearing white shirts with brown or tan shorts, white tights or socks, and dark shoes. To the left of them are the richly carved architectural remnants of stone archways, some decorated with coloured heraldic imagery. To the right, a building with a small spire and large window set in gothic style stone tracery. Westminster Abbey and a soft cloudy sky dominate the background.
The process of writing alt text for images of three-dimensional objects is almost identical. When describing these objects, we try to talk about what position the object is in, or the angle from which the photograph was taken. For example, the alt text we have for this object is:
A copper weathervane displayed standing upright. A cylindrical pole is attached to a wooden base. The bottom third of the pole is decoratively twisted. The middle section of the pole supports a metal flag extending sideways to the right hand side, with cut-out detailing including a stylised ‘V’ in gothic style type. Arrowhead shapes extend from the edges and corners of the flag. On the top of the central pole is a three-dimensional fleur de lys. The wooden base has moulded concentric circle details. The weathervane is photographed against a plain off-white background. The object overall appears brown, but the top of the object is a shinier copper tone.
A balancing act
It can be difficult to get the level of detail right when writing alt text. Describing a portrait of, for example, Winston Churchill, as literally ‘a portrait of Winston Churchill’ may seem appropriate, but it isn’t enough if someone doesn’t know what Winston Churchill looked like. The caption doesn’t tell us anything about the style of the portrait, the setting, the stage of life of the sitter, or any other details which the portrait may contain. At the other end of the spectrum, describing a complicated image can require a lot of detail which can quickly become overwhelming. It can be a challenge to strike the right balance. Here’s our example:
Colour portrait painting of Neville Chamberlain. Chamberlain is a middle aged man with short greying hair combed over, thick eyebrows and a grey moustache. He sits in a wooden chair with his hands clasped together, looking directly at the viewer with a neutral expression. He wears a three piece suit: black jacket with a white pocket square; grey pinstripe trousers; a cream waistcoat with pocket watch chain; and a white wing collar shirt and red tie. Behind Chamberlain is a large red curtain with gold tassel fringing. The portrait is painted in a realistic modern style with rich colours.
Alt text should steer clear of any personal interpretation or judgement. We only describe what we see in the image, not what we think might be happening or what the meaning of the image may be. This allows the user to come to their own conclusions about how to interpret the image.
How would you go about describing an abstract artwork?
Describing abstract images or objects requires it’s own approach. We’ve found it best to start by describing abstract objects in terms of their overall style, form and colours before talking about specific shapes, marks or compositions.
The alt text accompanying this image describes the shapes, colours, and overall layout:
Abstract print with a pink, black, blue and yellow colour scheme. The background consists of dark blue and black diagonal stripes with a wavy dark pink border. In front are seven dark pink curved and wavy shapes. The shapes are very thick lines that twist and curve in on themselves. Each shape has a thin yellow line running through the middle of it. Six of the dark pink shapes are a similar size, while the seventh is larger. The six smaller shapes are in the top half of the composition, while the seventh and larger one is in the bottom half.
In general, we have found that an alt text caption is successful when we read the image description to another person and they can imagine the image to a reasonable level of accuracy.
Although writing alt text can be challenging, the process also brings brilliant opportunities. By looking at each artwork individually we notice details we hadn’t spotted before. In some cases we have even deciphered artists’ signatures which were previously a mystery.
Improving accessibility is the job of the whole team, and we are continually trying to improve our alt text writing skills. In giving clear and concise alt text for Heritage Collections objects, we aim to bring the history of Parliament to many more people.