When you create a new weblog, or any other resource for that matter, it is created private. This mean that only you, and other people who you make as owners or managers can view or edit the contents. If you want your weblog to be private to only yourself, leave the settings as default. If you want only your supervisor to be able to read it, then add them as an owner or manager (under Sharing). If you want to allow everyone to read your blog, then make the blog visible.

When creating deciding when to create new weblogs, try organising them as follows:

1. Create a weblog by project area, such as thesis, work, and private;
2. Add topics specific to this area, ie code, reports, misc, etc;
3. Add other users who you want to be able to view your work; or make the entire weblog visible.

1. Public (visible) blog for all your rantings
2. Thesis (private) blog, which your supervisor has read access to.
3. A private blog, which no one has access to.