I should like first to mention a few provisional findings from some studies of the impact of particular television programmes on which I have been engaged in Oxford over the last four years, and then to consider their implications when it comes to measuring the general effects of the medium, and in particular the effect of people's values and standards of behaviour. I set out to assess the comprehension of a whole range of informative television programmes (not plays or entertainment items) on samples of the general public. In all, nearly 2000 people were tested in groups of about 30 at a time. The first and most noticeable finding was that the intake of ideas, so far as it could be expressed and assessed in words, is closely related to the amount of education a person has had. It is also closely related to his level of intelligence so far as that is reflected in an occupational scale based upon .degrees of skilled training required for a job, and derived by W. A. Belson when he was at the BBC's Audience Research Department from data supplied by P.E. Vernon. This intelligence factor came out. in different amounts of comprehension among the audience: for any one programme and also in the different proportions of viewers able to grasp the. essentials of one programme as compared with another.