From mybrotherjames.com
Some schools still do this. It can be kind of annoying. Letters of intent are basically schools asking you if you want to renew your contract, but don't guarantee that you'll have a job. It's completely biased and in their favour.They know who they're keeping and who they're not. They've also probably placed adverts to look for new teachers. Because of this, letters of intent can lead teachers on. After signing a letter of intent you may have to wait a while to get your new contract, if they decide to give you one. I've heard of some places wanting a couple months between the letter of intent and a new contract.
Now, most places do give everyone a contract who signs a letter of intent. However, you never know. And until you sign your contract on the dotted line, don't think that anything's set in stone.
