You want help text to be placed where the user has a question (e.g., “How do I apply this message to all the emails I’ve listed?”). You also want a control to be placed where the user is ready to activate it (e.g., “I’ve written my message and entered my emails, now I want to apply the message to all the emails.”). It follows that, in a properly laid out form, the help text should be near the control it relates to.
From what I’ve seen, instructions about specific controls in a centralized location (e.g., the top or bottom of the form) is a waste of space. Users don’t read them, believing they can figure out the form without them, and usually they’re right. If users do get stuck, they’re unlikely to be successful hunting around the form for help –they probably won’t find it among all the other irrelevant stuff filling the page.
So yes, put the help text as proximal as you can to the related control. There are 6 levels of proximity.
Make the help text be the control label. So instead of separate help text “to apply same message to all, click Apply to All,” you simply label the checkbox “[ ] Apply same message to all” (where [ ] is the checkbox).
Embed the control in the help text. This is most helpful to avoid long cluttering buttons with long captions. So you have “Apply same message to [All] emails,” where [All] is a command button, and the rest is static text.
Place the help text near the control. This is best for subsidiary or clarifying information that may not be apparent from the control itself. So you have “[Apply to All] --Sends message to all emails, logs the transaction, and waters the recipients’ cacti.” Sometimes section headers and titles (e.g., step labels) serve in this capacity.
Put the help text in a tooltip or balloon. This is generally best for when the users are wondering what a control does, rather than how can they complete the next intended step in the process. If you do it for one control, you probably should do it for all similar controls, otherwise users may never discover it (even then they may not). Tooltips regularly provide help text for all icons, for example. If the help text tends to be more than a few words, you may need to provide users with a means to turn the balloons on an off.
Add a Help link beside the control. This opens a popup or message box with the help text. The link could be simply a question mark. The popup can be self-dismissing, perhaps disappearing when the user releases the mouse button, thus making it more like a tooltip with better discoverability and user control.
Searchable help. Finally, you can provide a link or other controls at the top of the form for searchable help, where the user can enter “Send message to all emails” and get a window explaining how to do it. The controls need to be at the top of the form so users are likely to notice they’re there before they actually get stuck.
Level 1 is the most proximity, providing instantaneous help, while Level 6 is the least proximity, requiring the most work for the user, and, debatably, the least likelihood of success. You want the most proximity (e.g., Level 1, 2, 3) you can get away with. However, the high proximity levels tend to tolerate the least amount of help text before the form gets too long and cluttered. Certainly, in your case, where the help text is only two words longer than the control label, you can very likely use Level 1 or 2. You’ll have to go to lower proximities only if you have to provide more extensive instruction. If you’ve properly designed your form, the vast majority of users won’t need extensive instruction, so that shouldn’t happen too often. You can, and probably should, employ multiple levels in the same form, each successive level catching a smaller number of increasingly desperate users. Searchable help becomes the last resort.
There are rare cases of inherently complicated tasks or domains where users regularly need extensive instruction. If that’s the case for you, you need to re-think how you rollout your app. You may need to provide training, perhaps through on-line demonstrations and tutorials. Then you don't have to rely on help so much.
However, if you’re seeing a need for a lot of help text for the average user, then you should take a second look at your form design. As commenter Matt Obee points out, your form should be as self-documenting as possible.
Clear precise language may help. I know it’s only a mockup and I have no knowledge of the task, but it's not clear what “apply to everyone” means. Maybe the problem is your users don’t understand it either, in which case the help text won’t help no matter where it is. If you mean “email message to all addresses” say that, rather than “apply message to everyone.”
You have a list of emails the message applies to if the user selects Apply to All. So what does the message apply to if the user doesn’t select apply to all? Maybe you need two radio buttons –one with Apply to All next to the list of emails, and an alternative Apply to X (whatever X is). Or, if the alternative is for the user to select an email from the list, then what you need isn’t “Apply All” but “Select All.” Assuming you support multi-selection, this adds flexibility –a user can select all emails, then deselect certain emails (e.g., the guy the surprise party is for).
Remember you want the control to be placed where the user is ready to activate it. Right now it’s not clear what “all” or “everyone” means because the check box is far from the email addresses and separated by a border. Maybe you need to move the checkbox (or radio button) to the right side so it’s clear it means all the emails listed (not all the emails in the whole company or the whole world).
