I've had to make that decision myself on a number of occasions.
There are several different factors. Often one factor that can operate is in relation to limitation periods. If a longer period of time has elapsed since the date of the offence, you may have missed a limitation period that would have allowed you to proceed in a provincial court by summary conviction, in which case you can proceed by indictment.
I think usually, though, the main operating consideration is the seriousness of the offence. We have a lot of offences in our code that are, by design, broadly defined, in the sense that they can capture a really wide range of conduct. An assault would be a really good example of that. An assault can be relatively trivial on the spectrum or it can be a very serious offence. In considering whether to proceed summarily or by indictment, one of the things you'd be looking at is the seriousness of the offence. Related to that would be the punishment that you intend to seek because of the statutory maximums being lower for summary conviction offences than for indictable offences.
I want to highlight as well that a relevant piece in the hybridization is that, for these indictable offences that are, let's say, punishable by up to 10 years, there's nothing that stops a judge from sentencing someone to six or 12 months. It's not necessarily the case that sentences will be reduced by hybridizing and proceeding summarily, because there are many examples of offenders who are sentenced to far below the statutory maximum, even for straight indictable offences.