Monitoring Accessibility Services in Digital Television

Table 1

Checklist of checkpoints and evaluation guidelines defined for the manual verification of subtitling in television programmes.

N	Checkpoint	Checking-guideline
1	Programme name in EPG	Check if name in EPG corresponds with programme name
2	EPG synchronisation	Check if EPG information is updated when a programme starts, within a predetermined time window
3	Subtitle signalling	Check that subtitle icons appear in the on-screen display of the television set
4	Presence of subtitles	Activate Teletext subtitles and check whether they appear on the screen
		Activate DVB subtitles and check whether they appear on the screen
5	Subtitle position on screen	Check that speech subtitles are centred and in the lower part of the screen
		Check the position of sound effect subtitles
		Check that no overlays occur when open captions appear on screen
6	No. of lines of text in a subtitle	Get the maximum number of lines simultaneously displayed on the screen in prerecorded programmes
		Get the maximum number of lines simultaneously displayed on the screen in live programmes
7	Colour usage	Check whether colours are used to identify different characters in the programme
		Check if colour allocation is consistent throughout the entire programme
8	Subtitling speed	Check the time in which individual subtitles are displayed and their length to obtain maximum and average subtitling speeds
9	Subtitle grammatical correctness	Evaluate the level of orthographical and syntactical correctness of text
10	Subtitle literality	Evaluate how close subtitle and speech contents are
11	Subtitle synchronisation	Measure subtitle presentation times relative to corresponding speech fragments to obtain maximum and average offsets both in prerecorded and live programmes