Users Really DO Care About Your Interface

Last week I got a first-hand look at a user's reaction to a poorly designed interface. It made me smile.

I was in for a minor, routine medical procedure. The pre-op nurse was asking questions and entering my answers into the clinic's on-line medical records program. She noticed me staring at the screen and, perhaps thinking I was getting impatient (pardon the pun), felt she needed to apologize for how long it was taking. I assured her that I was mostly curious about the input process for professional reasons, having been a Relational Database Applicaton developer for many years. That prompted her to elaborate.

The system she was using required her to put in a couple of data points, then click a button or link to move to a different screen to add a few more data points, then move to a different screen for something else, and so on. She then explained that at her other job, they had a different system that allowed her to just scroll down as she entered data, without clicking and and waiting for a new screen to load. Much more efficient, at least in her opinion.

That told me a couple of things. First, she has joined the so-called Gig Economy and has, for better or worse, a variety of work environments to compare. Probably, she's not the only one doing that these days.

But more importantly, it told me that interface design is a big deal. I doubt that this particular nurse would give up a particular job because of it, but I would bet that if it came down to a choice between the two positions she holds, she is very much aware of, and concerned about, the usability of the tools available at the two.

Multi-Purpose Forms in an Access Relational Database Application

Microsoft Access is very flexible development tool. Seasoned developers know this, and take advantage of that flexibility in different ways. For example, different interface objects can be used for two or more purposes. A recent question at UtterAccess gave me an opportunity to create a small demo to illustrate how re-use of objects works.

In this demo Access Relational Database Application, I used one of the arguments for the DoCmd.OpenForm action to change the Data Mode for a single form.
Here's the full line of code, taken from two different procedures: 

    DoCmd.OpenForm FormName:="frmHousehold", View:=acNormal, DataMode:=acFormAdd

which runs from the Click Event of one Command Button. 


    DoCmd.OpenForm FormName:="frmHousehold", View:=acNormal, DataMode:=acFormEdit

which runs from the Click Event of the other Command Button. 

Two Command Buttons Open One Form in Two Different Data Modes

This is a very simple illustration of the re-use of objects. Instead of creating two different objects--add and edit forms in this case--to do two very similar tasks, we re-use the same object but vary the way it is used. Because adding records to a table, and editing records in that same table are almost identical tasks; it's obvious that we can simplify the Access Relational Database Application this way.

This is a simple example of a much broader set of design principles and practices. If you want to learn more, here's an excellent YouTube video by Phillip Steifel.
 
 

Pouring a Concrete Foundation After the Roof Goes On

Sometimes, when I'm cruising Access forums for questions I might be able to answer, I get the feeling that Access is simultaneously a really fantastic application-development tool and a really subtle trap for the unaware.

I'm talking about valid, proper, appropriate, NORMALIZED Relational Table Design, of course. Think, for example, of color options or size options for articles of clothing. Shirts come in Small, Medium, Large and Extra Large. Socks come in Blue, Black, Argyle or white. And so on. You've all seen "tables" in Excel worksheets, with one column for each option. In Excel they are the only option. You have to have different columns for each option.  And in the case of two options, you might even have combinations like "Small Blue", "Medium Blue", "Large Blue" and "Extra Large Blue", along with all of the other possible combinations. The inevitable result is multiple columns stretching out to the right as far as the eye can scroll.

Unfortunately, those columns make their way into Access tables as fields as well.

But in Access forums, the problem table design is seldom broached in the initial post, although I have seen a few direct questions about it.

The question often presents itself as a problem with designing an interface to handle multiple fields  Should you use a check box to select one of those options, or some other interface element that addresses each of those fields somehow?

Sometimes the question asks for help in constraining data when two or more fields are available, only one of which should be filled and the others left blank . If you pick a Large size shirt, you can't also have it be Small. Black socks can't also be White socks.

Sometimes it shows up as a problem getting results out of a query with that kind of inappropriate table design. How do I write a query to get the Shirt Size we sell most often?

There are many variations, but they all boil down to lack of Normalization, and I compare that to trying to go back and putting in a foundation under a house when you've already put up walls and a roof. It's possible, but it's not going to be easy and it all might collapse on you.

If you plan to create an Access Relational Database Application, and if you don't know what I am talking about here, I think you owe it to yourself to invest a few hours in your peace of mind by learning as much as you can about the Rules of Normalization BEFORE you try to put up walls and a a roof.  The nicest roof in the world won't keep the rain out if the building collapses because it lacks a foundation.

The reason this is a problem is that, as I said at the beginning, Access is really open and easy to get started. It's tempting to import a working spreadsheet and throw an interface on. And, unfortunately, that can be done without understanding what the consequences will be.

Be safe, stay dry. Normalize first.

Why Choose Min() and Max() Over First() and Last() ?

Humans are much better than computers at resolving ambiguity. We're trained from birth to do that.

People can look at a series, or list, of values and decide which one is "the first" and which one is "the last" by referencing both the values themselves and the context in which the question was asked.

Perhaps such a  question might be "Of this list of people and their birthdates, which birthdate came first?"

We don't need to have the birthdays sorted in date order to answer that question because our minds are trained to recognize the context as well as the values. For example, if the list of birthdates is presented to us with the names of the people sorted alphabetically, we don't go to the item at the top of the list and pick it because know that's not the right context; we scan the entire list looking for the earliest one relative to other birthdates.

That kind of disambiguation is a skill computers are still learning, and one which Relational Database Applications are not set up to handle directly. We still need to make explicit the Sort Order the computer must use in order to find "the first".

Put it a different way.

If the question is phrased as it is above, the sort must be "earliest" birthdate to "most recent" birthdate so that the "earliest" is also "first" on the resulting set of records.

If the question is phrased differently, the sort must be different. "Of this list of people and their birthdates, which one is the birthdate of the  first person on the list?"

To answer that question, of course, we have to know which sort order to apply to the list to get the result expected by the questioner. Do they want the "first" person alphabetically? Alphabetically by FirstName? Alphabetically by LastName? Or does "first" refer to some other criteria like "tallest", "top producer", etc?

When the question is asked explicitly, it's easy to see why and how the answer will be different. We're asking about birthdates in different contexts, and that means  first doesn't always return the same answer.

Because of that ambiguity, many seasoned Access developers prefer to use Min() and Max() instead of First() and Last(). Min() and Max() are absolutes within the values themselves, regardless of context. The Minimum birthdate is the same regardless of any sort applied any of the other fields in that query. The same is true for Maximum birthdate. Access doesn't need to disambiguate the contextual reference for the question, "What is the minimum (or earliest) birthdate in this list of people and their birthdates?"

While it is possible to get accurate results when using First() and Last(), doing so depends on knowing both the values and the context in which the comparison is being made.

If you want to continue to use First() and Last() instead of Min() and Max(), continue to do so. Just keep in mind the possibility of potential subtle errors and make sure you use the appropriate ORDER BY clause.

First and Last refer to position in a list. Min and Max refer to values in one field.

Green is for Go, Yellow is for Slow, Red is for No.

Calculated Values Stored in Fields Don't Pay, They Cost

Most people who spend a lot of time around relational database applications develop a phobia for calculated values stored in tables. I am aware of arguments for special cases that justify doing it anyway. However, the general rule is a sound one: Don't calculate and store values in tables.

I have repeated this rule innumerable times myself. At a recent family gathering, though, I heard a story that explains just how awful the consequences of ignoring this rule can be. I thought I'd share the story here, subject to the usual disclaimers about changing or concealing details to protect privacy of those involved.

This company is in the communications business in a general sense. They install hardware and software along with other supporting infrastructure in order to provide their particular services to both commercial and residential customers. They maintain a number of very large databases, one of which details existing customer accounts, another of which details existing infrastructure previously installed in homes and business locations. In other words, their technical people track where they've installed hardware and other equipment in their area of operations in one database. Their accounting  people track customers and the locations where they receive services. Two different databases built around similar, but different data.

Salespersons contact potential customers to negotiate contracts for those services. Part of that process involves requesting information from their technical side about what infrastructure might already be installed at a location, perhaps for a previous occupant of that location. That communication takes some time, slowing down the negotiation. And, as we all know, time is money, especially for a busy salesperson. Somebody came up with the great idea of creating a third system that draws data from both of the other databases, synthesized, of course, for the salesperson. That way, they could provide a simple dashboard style look at any given location that would compare existing hardware and software at a site to the requirement specified in the potential contract at that site and flash one of three or four statuses. Let's say, for the sake of discussion, that "green" means the location needs no modifications to work for THAT contract, "yellow" means minor upgrades or changes, while "red' means the costs of making the required changes would be too great for the potential revenue that would be generated by that contract (unless the customer is willing to pick up the tab).

With that tool in place, a salesperson (or more likely the staff tasked with data entry) can enter the location and the services requested on a potential contract and get a status back right away. They have the option at that point, to sign the contract if it's "green", renegotiate based on a "yellow" status, or inform the potential customer right away that they can't meet their request on "red". Great, saving time means the salesperson moves quicker and earns more. Everyone's happier. 

Unfortunately, that status is a calculated value and it is STORED ONLY in the salesperson's system . Not in the technical database and not in the existing accounts database (it's irrelevant to both of them). And of all of the people who use the system, the marketing and sales people are, perhaps, the least likely to understand why that's a problem for them.

In fact, that's where things went off the tracks one day. 

A salesperson negotiated a new contract with a potential customer moving into a new space. The proposed contract went back to the office where a data entry person entered it into their sales system. The location and services requested flashed "yellow", meaning it would be possible to accept the contract, but the location would need some modifications. The company was even willing to pay for those minor modifications in anticipation of the revenue the contract could be expected to generate. 

The salesperson goes back, explains the situation, gets a new agreement to delay installation until a crew could come and modify infrastructure. In this case, the customer would also have to accept a crew interrupting normal  operations. Agreed. That must be a good salesperson, right?

So, the company sends out a sub-contractor to make the modifications. They submit an invoice for the work done and get paid. 

Now, the data entry person tries to reenter the new contract, knowing the location now meets the "green" status. Uh, no. The SALESPERSON's system still shows "yellow". What? It seems that the subcontractor was paid, but there was no proof they actually DID the work. Either the infrastructure database was not updated properly, or the subcontractor scammed them. Hm.

So, another delay has to be negotiated with the potential customer while still another crew is sent out to inspect. And YES! the work was done. Good to go, except the keeper of the infrastructure database refuses to update it until they get the subcontractor's written summary of the work. Another delay while they contact the subcontractor to get the required paperwork. The subcontractor tells them it was already submitted along with the invoice, but they'll be happy to go out again to fill out the paperwork. After all, they can't be expected to blindly fill out the required document without an inspection by their own people. And, by the way, they gave the company the only copy of their document. Hm. Double-dipping, perhaps? Super cautious, maybe?

Anyway, the salesperson has a problem. Still another negotiated delay while the paperwork dance is working it's way through the bureaucracy, OR (sly wink), simply change the CALCULATED  value from "yellow" to "green", allowing the system to accept the contract so he can get paid. And that's what happened. All happy now, right?

Well, not quite yet. The salesperson sets a date for the final install, gets his commission check, and moves on to the next sale.

Not so fast. When the company's install crew arrives on site to do the final work, THEIR database still shows deficiencies. And they refuse to install. Everyone insists it's all good, but if you get in the habit of overriding your system, sooner or later you're going to be sorry. No install until they get the document that shows the required work was done.

The salesperson has no choice but to ask the potential customer to delay once more and allow another crew to come out and verify their first crew did their work. At this point, the customer said, "enough is enough" and the deal was cancelled.  The commission had to be clawed back in the salesperson's next check.

So, this story involves a number of problems, and the storage of a calculated value is just one. The subcontractor may, or may not, have been playing fair. The bright bulb who adjusted the status from "yellow" to "green" probably didn't even know the trap they had just set. A combination of rigid rules and the need for accountability combined to sabotage things.  But none of it would have happened except for that short-cut that allowed the calculated value to be stored--and updated manually.