protection – Tim Gee's Blog

In a recent post, we discussed how you might like to set up some simple protection in your shared spreadsheet, to prevent other users from entering incorrect data into the wrong cells or ranges. But if you are slightly more ambitious with this concept, and are keen to steer your colleagues or any other users along the correct path in their use of your shared spreadsheet, you might choose to take your security to the next level by taking advantage of a feature called validation. In this way, you can not just determine whether or not other users can type into particular cells, but what they can actually type (i.e. numbers within a particular range, valid department names chosen from a list etc.) Used judiciously, it can be a very effective way to avoid errors or corruption in your spreadsheet that might otherwise undermine your entire efforts.

When using this feature for the first time, a good practice can be to try it out on just one cell, as a test case; you can easily copy or extend your validation settings to a larger or longer range afterwards, an option that we will discuss in more detail below.

First, select the desired cell that you want to use as your test case, and then select ‘Data Validation’ from the Data tab. If need be, select the leftmost tab called “Settings” in this screen, and select the type of value you are working with from the ‘Allow’ menu, such as ‘Whole number’:

Once you have made this selection, you can define your required the parameters in the lower part of this screen (i.e greater than, less than, between etc.). This choice alone will define the validation rule for your selected cell; should you now immediately select OK at the foot of this screen, the user would need to follow this rule when entering values into this cell. Should they err in this process, a warning will appear to inform of their transgression:

The message is rather vague and therefore unhelpful. You might well choose to customise this message and make it more personalised and enlightening to your fellow user. You can do so via the ‘’Error Alerts” tab in the same original Data Validation window. Here you can select which icon to display in your warning, give it a suitable title, and then type your desired, appropriate content in the ‘Error Message’ box on the right hand side.

You can provide even more guidance to your users in the same Data Validation screen, via the ‘Input message’ tab. The input message is a prompt that appears on the screen when you first select the cell with the validation settings defined, and can alert the user, if required, as to what they should be typing to do the right thing and avoid error. Your Data Validation rule can potentially include all three features:

The essential Settings that define the rule to control any entry in the chosen cell(s). This is the only mandatory part of this feature.

An Input Message to inform the user of the rule’s requirements

An Error Alert that appears if the user ignores the prompt and makes the error.

It might be tempting to personalise your error message in an attempt to be humorous or derogatory. (For example, “Wrong number, you muppet!”). This is an impulse best restrained, especially in our current litigious age. You are on much safer ground with a more neutral, encouraging message. An example might be of the “Bad luck, try again” ilk, with an explanation of why their entry was in error and how they might correct it.

If your validation settings are working for you on your ‘test case’ cell, you can extend the validation to a larger range easily. All you need to do is to select the range required, along with your test case cell. Then, you can simply select the same Data Validation option on the Data tab,and you will be presented with the following screen:

Click on Yes, and all of the cells would have the exact same validation rule.

If you acquire confidence in the use of this validation feature, you can be quite creative with it. For example, if your spreadsheet needs to filled in with some text values, for example department or suburb names, you can use validation to define a list in an interactive menu that your user can choose a valid entry from. Look for a post in the near future on this subject.

Few things in your working life are more guaranteed to cause exasperation than the challenges posed by the need for collaboration with your colleagues. In the context of Microsoft Excel, a frequent source of consternation is sharing a spreadsheet that you have created and refined with great care, only to have the sharer sabotage your efforts (inadvertently or otherwise) by typing over your formula cells, or entering entirely inappropriate data in the wrong location, thereby corrupting your spreadsheet content at the cost of significant time and effort.

Happily, Excel has some simple security features that can help you to prevent this kind of calamity afflicting your spreadsheets. The easiest and simplest of these is the facility of locking cells that you don’t want others to tamper with.

To achieve this, all you need to do is follow these simple steps:

Select the cells, or the range of cells, that you want to be available to other users.

Right-click somewhere over these selected cells and choose Format Cells on the menu

On the right-most tab in this screen called Protection, make sure that the ‘Locked’ check box is un-ticked, hence making sure that all your selected cells are unlocked.

At first encounter, this might seem a trifle counter-intuitive; unlocking cells before you ever lock them. It is important to realise that the default status of all the cells in your worksheet is ‘locked’, which means that if you decide to lock (protect) the entire spreadsheet, theses cells will be locked as well. Once you have thus unlocked the cells that you wish to be available to others, you can then enforce protection on the rest of the spreadsheet via selecting the ‘Protect Sheet’ button on the Review tab. This screen also gives you the option to add another level of security by defining a password to unlock the spreadsheet:

Note that you also have the option in this screen to control how much access other users have to be able to modify or utilise the spreadsheet contents. If you really want to enforce a stringent level of security on your spreadsheet, you might choose to check all the boxes in the lower part of the Protect Sheet screen. Thus, if you then go on to lock the spreadsheet, the other user will be severely constrained in what they can do with your spreadsheet. The main consideration here is really how much confidence you have in the Excel knowledge of your colleagues who might share the spreadsheet. You can, of course, go too far with this form of security, and limit your colleague’s use of the spreadsheet to such an extent that you seriously impede their effectiveness and productivity. As in most things, the wise choice would be to consult with your fellow users first and establish some clear policies for best practice.Once you have defined your password (if required), you can click on OK to finish the process. (You will be required to re-enter your password for confirmation.) Then, if you try and enter or modify the contents of any cells other than those that have unlocked, you will find that you will be unable to so.

To unlock the spreadsheet if required, just select the same ‘Protect Sheet’ button on the Review tab. You will be asked to enter your password to proceed, and if you do so correctly and click on OK, you will be back to square one, with your spreadsheet once again fully accessible to all comers.

This, of course, is just one level of security available in your Excel spreadsheet. If you want to be able to control not only whether or not other users can enter data into specific cells, but exactly what they can enter (i.e. numbers within a particular range, valid department names chosen from a list etc.), you might like to define a validation rule for some ranges within your spreadsheet. Look for more detailed discussion of the validation feature in the near future. In the meantime, check out more advice and info about Excel here.