MessagEase for the Palm OS and Pocket PC
Posted April 2004 by By Tanker Bob

Text messaging over your cell phone can be an exercise in frustration. Even with T9, messaging requires patience and endurance. Some simply accept the inconvenience. Others look for a better way. Dr. Saied Nesbat took his PhD in Electrical Engineering and rose to the challenge, starting ExIdeas, Inc. Dr. Nesbat researched the literature, taught himself user interface design, and created a complete and useful text input system using just the 12 keys on a cell phone. After completing that project for hard key devices, he applied that the same input system to “soft key” environments and birthed MessagEase for Palm OS, Pocket PC and tablet PCs.

As one would expect from a PhD in EE, Dr. Nesbat based the design for MessagEase on sound analytical principles. He used Fitts' Law, the concept that the time to acquire a target is a function of the distance to and size of the target put into mathematical terms, as a starting point. He combined this with M. S. Mayzner and N.E. Tresselt's tables of single-letter and digram (2-letter combinations) frequencies for various word-length and letter-position combinations in their 1965 Psychonomic Monograph Supplement s. Dr. Nesbat used his background in design-for-test to mathematically optimize the letter placement based on all these factors. After considerable optimization, the resultant compact MessagEase (ME) took text input systems to a new high. You can read his original paper in PDF format here.

The overall keyboard design actually uses two primary keypads. As you can see from the illustration, ME uses just nine keys to enter the entire 26-character English alphabet. The nine most common letters— E, T, A, O, N, I, S, and H—account for about 71% of the English usage and appear on the nine main keys. Just tap them to get them. For the most part, the next eight most common letters appear around the center ‘O'. The user accesses these by putting the stylus down anywhere in the ‘O' key and sliding in the appropriate direction. Except for the least common letter ‘Z', the rest appear such that a stroke towards center from the outside keys brings them up. I said for the most part because the math showed little speed gain for some of the secondary letter placements. Dr. Nesbat decided to place the rounded secondary characters around the ‘O' and the angular letters on the outside for ease of learning, carefully located to produce no real loss of performance. Thus, the entire alphabet can be accessed by either a tap or tap-and-slide with just nine keys. This all resulted in an extremely fast “keyboard” that's relatively quick to learn.

The numbers and punctuation appear on the other side of the input area. The spacebar, which is the “letter” of the most frequency occurrence in writing (18.7% vs. ‘E' at 13.3% when space is considered a 27th “letter”), occupies a large part of the middle ground for speedy targeting. Although the punctuation appears on the number pad, it also comes up from the letter pad from the points not occupied by letters. For example, stroking left on the number 3 produces a ‘?', and down on ‘E' a period. All the common punctuation may be accessed in this way. This includes common digrams involving the space bar. Period, colon, semi-colon, and comma all drag down towards the space bar which almost always succeeds them in normal writing. All this minimizes hand movements during normal text entry to almost nothing.

MessagEase also easily handles special characters. Accented, etc., letters can be done in several ways. The user can enter a letter and its accent in succession, then stroke up to the NNW direction on the ‘A' key to combine the letter and accent into a single accented letter. Sliding back and forth on some letter keys also produces a special character, and the manual lists all those. Lastly, the keys can be reprogrammed (see below), and you can add your most-used special characters to the keyboard itself.

At the center of the keyboard are two special keys. The top-center key puts all the common Palm functions just a stroke away. These include copy, cut, paste, undo, shortcut, and the command stroke, as well as moving to the next or previous database field. The “Star” key below it can be programmed by the user, which we'll discuss below.

I tested MessagEase (ME) on my Palm Tungsten|T3. This version, MessagEase4T3 (ME4T3) 1.7, installs as a replacement for the middle Graffiti 2 input skin (the one with three input panels) on the Palm's Dynamic Input Area (DIA). ME or Graffiti 2 can be selected by tapping on their keys on either side of the keyboard itself, and the core Palm functions like Home and Menu are likewise present. The skin colors match the T3's stock status bar nicely. ME4T3 works in portrait and landscape on the T3, which at this writing is unique amongst non-QWERTY keyboards. The layout of the panel suits it well for varying screen orientations.

Upon installation and execution of the control program, you select which keyboard layout that you prefer. The installation of new keyboards couldn't be simpler. The choices include letters on the left or right, and on the stamps for other PDAs, a special keyboard with just the letters and numbers for experienced users. The T3 DIA implementation doesn't require calibration, but the stamps for other units may require it to ensure accurate input.

Setup options provide what you'd expect. Drag length to obtain characters can be set as desired. Circling on the main letters can either produce numbers clockwise or counter-clockwise, or you can have ME capitalize the letter circled upon. You can set the up/down arrows on the system key to change pages, selection, or fields. The next option either protects the letter/number keys as preprogrammed or allows you to reprogram them with special characters for another language. The checkboxes can set auto capitalization, key clicking, or fix problems in the last two pixel rows of some handhelds.

Perhaps the greatest strength of the MessagEase system comes from its macro support. ME supports 32 special macro commands, all of which can be applied to various parts of the keyboard. It can also store/recall text strings as well. Words can't begin to capture the power of this capability. The Star key is reserved for users to program with these macros for easy access. Key assignments and macros can be viewed using the ‘?' key at the bottom of the keyboard. I listed my Star key macros in the illustration. They include changing word capitalization to all upper, all lower, sentence case, and title case, and select text to beginning and end of the line. The manual lists the special macros in addition to the entire ASCII code compendium for those that want to customize their keyboard.

What factors make MessagEase unique amongst alternate keyboard offerings? First, its compactness, packing the alphabet into just a few keys. This keeps hand movement to an absolute minimum while making it useful on smart cards as well. It also allows the individual keys to be larger than normal keyboard layouts, improving accuracy and speed. Second, because of its roots in Fitts' Law, it can be scaled in size within reason. Thus it works just as well on PDAs and tablet PCs, and perhaps applications not yet considered. Third, ME is platform independent. The core letter keypad is basically a 3 x 4 pattern, which cell phones, security keypads, calculators, and other devices use. The possibilities are almost endless.

So, how does it work? Marvelously! I'm no speed demon at text input of any kind. My Graffiti input maxed out around 12 words per minute or so on a great day, not even counting all my errors. I could never take notes in a meeting with Graffiti 1 or 2. I've been able to do just over 25 WPM with other soft keyboards—nothing to sneeze at but still not note taking speed. MessagEase brought my input up to over 35 WPM, which is really flying for me. Writing normal text requires almost an infinitesimal amount of hand movement. This is borne out by a paper done by Shumin Zhai, Michael Hunter, and Barton Smith available in PDF format here, which compares a variety of keyboard layouts using Fitts' Law. Dr. Nesbat used their methodology to test MessagEase under identical conditions, and recorded the results in his paper cited earlier. Their scientific results match my own experience. I use the text-editing macros every day. Like any input method, ME has an associated learning curve. Dr. Nesbat minimized this by his clever placement of the letter sets, but it still takes a bit of practice to become proficient.

MessagEase proved a joy to use, looked great, and increased my text input speed by 41%. The well-thought-out compact keypad, powerful macro capability, ready access to numbers and a wide variety of punctuation/symbols, and landscape support for the T3 set MessagEase apart from its competition. MessagEase can also be had as a stand-alone program and MessagEaseKB, a replacement for the built-in Palm soft keyboard. The latter can be particularly handy if you own a Palm Tungsten T model and want to write without opening your slider. Other versions of ME support other Palm OS PDAs, Pocket PC handhelds and Tablet PCs. Available as shareware for just $22.50, ME4T3 has returned as my primary, indeed only, input method for my Tungsten|T3.