The impact of technological change on the nature of work is twofold: new technologies may 1) cause changes in what workers do within their occupation or 2) cause workers to change occupations. To quantify these two effects, we match occupational data from the 2006 and 2016 Canadian censuses with detailed data that associate each occupation with measures of the skills and competencies required to perform that occupation. Our results show that the importance of attributes dealing with social interactions and non-routine cognitive tasks increased strongly (even more for men than for women), while the growth in the importance of attributes concerning manual tasks was small and sometimes even negative. Also, we find that changes in the importance of attributes come primarily from changes within occupations rather than from movement of workers between occupations.