This thesis is about patterns in the way viewers rate their appreciation (i.e. their liking or enjoyment) of television programmes. It is based on the analysis of an extensive set of previously confidential UK panel data, and involves replicating and building upon a well-established body of prior work. The major conclusions reached are: - Individual viewers can be segmented (on both behavioural and attitudinal bases) using this type of audience appreciation data. - Differences in the audience composition of programmes (i.e. certain programmes might attract audience segments that tend to give higher average appreciation scores) do not provide a simple explanation for systematic variations in the aggregate appreciation scores achieved by different programmes and by different programme types or genres. Limited evidence is found in support of a 'narrowcasting' proposition (i.e. where certain programmes might be expected to reach small, well-defined, and especially involved or appreciative audiences). This is not however the strong pattern that many practitioners might expect. There is no evidence, even in extreme cases, of any programmes that are watched by very targeted and highly appreciative audiences. There are systematic relationships between audience appreciation ratings and more traditional television ratings of audience size. When allowances are made for scheduling factors, programme type effects, and variations in audience composition, the size of a programme's audience is positively related to the appreciation viewers have for it. There is a strong relationship between appreciation and frequency of viewing. Programmes which achieve higher average appreciation scores also have higher levels of repeat viewing. Overall, these patterns suggest a positive but limited future role for audience appreciation ratings as a supplementary media planning measure. The data presentation methods and findings outlined in this thesis should provide a useful guide to help aid the interpretation of results from subsequent studies.