ca.yorku.cse.mack.fittstouch

Class FittsTouchActivity

java.lang.Object

android.content.Context

android.content.ContextWrapper

android.view.ContextThemeWrapper

android.app.Activity

ca.yorku.cse.mack.fittstouch.FittsTouchActivity

All Implemented Interfaces:

android.content.ComponentCallbacks, android.content.ComponentCallbacks2, android.view.KeyEvent.Callback, android.view.LayoutInflater.Factory, android.view.LayoutInflater.Factory2, android.view.View.OnCreateContextMenuListener, android.view.View.OnTouchListener, android.view.Window.Callback

public class FittsTouchActivity
extends android.app.Activity
implements android.view.View.OnTouchListener

FittsTouch

Summary

• Android experiment software for evaluating touch-based target selection using Fitts' law.

• Implements both the two-dimensional (2D) and one-dimensional (1D) Fitts' law tasks described in ISO 9241-9 (updated in 2012 as ISO/TC 9241-411).

• User performance data gathered and saved in output files for follow-up analyses.

Related References

The following publications present research where this software was used:

• "Fitts' Throughput and the Remarkable Case of Touch-based Target Selection", by MacKenzie (HCII 2015)

• "Creating Fitts' Law Predictions for a Touchscreen Tablet", by Dunagan and Schofield (Int J Information and Communication Technology Research, 2016)

• "Tapping Task Performance on Smartphones in Cold Temperature", by Goncalves, Sarsenbayeva, van Berkel, Luo, Hosio, Risanen, Rintamäki, and Kostakos (Interacting with Computers, 2016)

• "Towards Improving Touchscreen Input Speed and Accuracy on Smartphones for Tremor Affected Persons", by Plaumann, Babic, Drey, Hepting, Stooß, and Rukzio (Proc UbiComp 2016)

• "Assessment of Mobile Interaction Performance in Cold Environments", by Sarsenbayeva (MSc Thesis, University of Oulu, Finland, 2016)

• "Improving Input Accuracy on Smartphones for Persons Who Are Affected by Tremor Using Motion Sensors", by Plaumann, Babic, Drey, Hepting, Stooss, & Rukzio (Proc ACM Conference on Interactive, Mobile, Wearable and Ubiquitous Technologies, 2017)

The following publications provide background information on Fitts' law and experimental testing using the Fitts' paradigm.

• "Towards a Standard for Pointing Device Avaluation: Perspectives on 27 Years of Fitts' Law Research in HCI", by Soukoreff and MacKenzie (IJHCS 2004).

• "Fitts' Law as a Research and Design Tool in Human-Computer Interaction", by MacKenzie (HCI 1992).

Setup Parameters

Upon launching, the program presents a setup dialog:

The parameters are embedded in the application. The default settings (shown) may be changed by selecting the corresponding spinner. Changes may be saved. Saved changes become the default settings when the application is next launched.

The setup parameters are as follows:

Parameter	Description
Participant code	Identifies the current participant.
Session code	Identifies the session. This code is useful if testing proceeds over multiple sessions to gauge the progression of learning.
Block code (auto)	Identifies the block of testing. This code is generated automatically. The first block of testing is "B01", then "B02", and so on. Output data files include the block code in the filename. The first available block code is used in opening data files for output. This prevents overwriting data from an earlier block of testing.
Group code	Identifies the group to which the participant was assigned. This code is needed if counterbalancing was used (i.e., participants were assigned to groups to offset order effects). This is common practice for testing the levels of a within-subjects independent variable.
Condition code	An arbitrary code to associate a test condition with a block of trials. This parameter might be useful if the user study includes conditions that are not inherently part of the application (e.g., Gender → male, female; User stance → sitting, standing, walking).
Mode	Set to either "1D" or "2D" to control whether the task is one-dimensional or two-dimensional.
NOTE: The setup parameters above appear in the filename for the output data files (e.g., FittsTouch-P01-S01-B01-G01-C01-1D.sd1). They also appear as data columns in the output data files.
Number of trials (1D)	Specifies the number of back-and-forth selections in a block of trials. This setup parameter is only relevant if Mode = 1D.
Number of targets (2D)	Specifies the number of targets that appear in the layout circle. This setup parameter is only relevant if Mode = 2D.
Target amplitude (A)	Specifies either the diameter of the layout circle (2D) or the center-to-center distance between targets (1D). The spinner offers three choices: "120, 240, 480", "250, 500", or "500" (but see note 2 below).
Target width (W)	Specifies the width of targets. This is either the diameter of the target circles (2D) or the width of the rectangles (1D). The spinner offers three choices: "60, 100", "30, 60, 120", or "100", Notes: 1. The total number of A-W conditions (sequences) in a block is n × m, where n is the number of target amplitudes and m is the number of target widths. 2. The A-W values are scaled such that the widest condition (largest A, largest W) spans the device's display with minus 10 pixels on each side.
Vibrotactile feedback	A checkbox parameter. If checked, a 10 ms vibrotactile pulse is emitted if a target is selected in error (i.e., the finger tap is outside the target).
Audio feedback	A checkbox parameter. If checked, an auditory beep is heard if a target is selected in error (i.e., the finger tap is outside the target).

Operation

Once the setup parameters are chosen, the testing begins by tapping "OK". The first screen to appear is a transition screen to ensure the participant is ready (below, left). Once the blue circle is tapped, the first test condition appears. Example are shown below for the 2D task (below, center) and the 1D task (below, right).

The participant selects targets by tapping with a finger. The target to tap is highlighted. Upon selection, the highlight moves to a target on the opposite side of the layout circle (2D) or to the opposing target (1D). Tapping continues until all targets are selected (2D) or until the specified number of trials is completed (1D).

The first tap to start a sequence must be correctly on the initial highlighted target. After a sequence is started, errors are permitted. If the user attempts to tap a target and the selection coordinate on finger-lift is outside the target, an error occurs. Vibrotactile or auditory feedback is emitted if the corresponding setup parameter was checked. Whether the target was hit or missed, the highlight moves to the next target.

A series of trials for a single A-W condition is called a "sequence". At the end of each sequence, results appear on the display. See below:

Once all the A-W conditions in a block are finished, the application terminates. User performance data are saved files for follow-up analyses. The data files are located in the device's public storage directory in a folder named FittsTouchData.

Output Data Files

For each block of testing, two output data files are created: sd1 and sd2. ("sd" is for "summary data".) The data are comma delimited for easy importing into a spreadsheet or statistics program.

sd1 Output File

The sd1 file contains the following summary data for each trial:

      Participant - participant code
      Session - session code
      Block - block code
      Group - group code
      Condition - condition code
      Mode - mode code (1D or 2D)
      Trial - trial number
      A - target amplitude
      W - target width
      FromX - x coordinate of center of from-target
      FromY - y coordinate of center of from-target
      TargetX - x coordinate of center of to-target
      TargetY - y coordinate of center of to-target
      FingerDownX - x coordinate of finger-down event at end of trial
      FingerDownY - y coordinate of finger-down event at end of trial
      SelectX - x coordinate of finger-up event at end of trial (target selection)
      SelectY - y coordinate of finger-up event at end of trial (target selection)
      xDelta - (see below)
      FingerDownUpDelta - Pythagorean distance between finger-down and finger-up events
      FingerDownUpTime - time in ms between finger-down and finger-up events
      DistanceFromTargetCenter - Pythagorean distance from selection coordinate to target center
      Miss - 0 = target selected, 1 = target missed
      MT - movement time in ms for the trial
 

Note: All sizes, distances, and coordinates are in pixel units for the test device.

xDelta is the x-distance from the selection coordinate to the center of the target. It is normalized relative to the center of the target and to the task axis. For example, xDelta = 1 is the equivalent of a one-pixel overshoot while xDelta = −1 is the equivalent of a one-pixel undershoot. Note that xDelta = 0 does not mean selection was precisely at the centre of the target. It means the selection was on a line orthogonal to the task axis going through the centre of the target. This is consistent with the inherently one-dimensional nature of Fitts' law.

xDelta is important for calculating Fitts' throughput. The standard deviation in the xDelta values collected over a sequence of trials is SD_x. This is used in the calculation of throughput (TP) as follows:

W_e = 4.133 × SD_x

ID_e = log₂(A_e / W_e + 1)

TP = ID_e / MT

sd2 Output File

The sd2 file contains summary data for a sequence of trials:

      Participant - participant code
      Session - session code
      Block - block code
      Group - group code
      Condition - condition code
      Mode - mode code (1D or 2D)
      Trials - number of trials in the sequence
      SequenceRepeatCount - number of times the sequence was repeated (see below)
      A - specified target amplitude
      W - specified target width
      ID - specified index of difficulty
      Ae - actual or effective movement amplitude
      We - actual or effective target width
      IDe - actual or effective index of difficulty
      MT - mean movement time in ms over all trials in the sequence
      ErrorRate - error rate (%)
      TP - Fitts' throughput in bits per second
 

The SequenceRepeatCount is used in conjunction with an outlier criterion. Any trial where the actual distance traversed is less the ½ the specified amplitude is deemed an outlier. The most likely cause of an outlier is either an inadvertent double-tap or a missed tap. A sequence with 1 or more outliers is an outlier sequence and is repeated. If this occurs, an alert popup appears at the end of the sequence to inform the participant. No data are saved for an outlier sequence. However, the SequenceRepeatCount entry in the sd2 file indicates the number of times the sequence was repeated due to the outlier criterion. Usually, SequenceRepeatCount = 0 (hopefully!).

The last six entries in the sd2 file are user performance measures. These reflect how the user actually performed while doing the sequence of trials. The measures most commonly used as dependent variables in Fitts' law experiments are the last three: movement time, error rate, and throughput.

The following are examples of "sd" (summary data) files:

• sd1 example
• sd2 example

Actual output files use "FittsTouch" as the base filename. This is followed by the participant code, the session code, the block code, the group code, the condition code, and the mode, for example, FittsTouch-P01-S01-B01-G01-C01-1D.sd1.

In most cases, the sd2 data files are the primary files used for data analyses in an experimental evaluation. The data in the sd2 files are full-precision, comma-delimited, to facilitate importing into a spreadsheet or statistics application. Below is an example for the sd2 file above, after importing into Microsoft Excel: (click to enlarge)

When using this application in an experiment, it is a good idea to terminate all other applications and to disable the system's WiFi and Bluetooth transceivers. This will maintain the integrity of the data collected and ensure that the application runs without hesitations.

Author:

(c) Scott MacKenzie, 2013-2017

Field Summary

Fields inherited from class android.app.Activity

DEFAULT_KEYS_DIALER, DEFAULT_KEYS_DISABLE, DEFAULT_KEYS_SEARCH_GLOBAL, DEFAULT_KEYS_SEARCH_LOCAL, DEFAULT_KEYS_SHORTCUT, FOCUSED_STATE_SET, RESULT_CANCELED, RESULT_FIRST_USER, RESULT_OK

Fields inherited from class android.content.Context

ACCESSIBILITY_SERVICE, ACCOUNT_SERVICE, ACTIVITY_SERVICE, ALARM_SERVICE, APP_OPS_SERVICE, APPWIDGET_SERVICE, AUDIO_SERVICE, BATTERY_SERVICE, BIND_ABOVE_CLIENT, BIND_ADJUST_WITH_ACTIVITY, BIND_ALLOW_OOM_MANAGEMENT, BIND_AUTO_CREATE, BIND_DEBUG_UNBIND, BIND_EXTERNAL_SERVICE, BIND_IMPORTANT, BIND_NOT_FOREGROUND, BIND_WAIVE_PRIORITY, BLUETOOTH_SERVICE, CAMERA_SERVICE, CAPTIONING_SERVICE, CARRIER_CONFIG_SERVICE, CLIPBOARD_SERVICE, CONNECTIVITY_SERVICE, CONSUMER_IR_SERVICE, CONTEXT_IGNORE_SECURITY, CONTEXT_INCLUDE_CODE, CONTEXT_RESTRICTED, DEVICE_POLICY_SERVICE, DISPLAY_SERVICE, DOWNLOAD_SERVICE, DROPBOX_SERVICE, FINGERPRINT_SERVICE, HARDWARE_PROPERTIES_SERVICE, INPUT_METHOD_SERVICE, INPUT_SERVICE, JOB_SCHEDULER_SERVICE, KEYGUARD_SERVICE, LAUNCHER_APPS_SERVICE, LAYOUT_INFLATER_SERVICE, LOCATION_SERVICE, MEDIA_PROJECTION_SERVICE, MEDIA_ROUTER_SERVICE, MEDIA_SESSION_SERVICE, MIDI_SERVICE, MODE_APPEND, MODE_ENABLE_WRITE_AHEAD_LOGGING, MODE_MULTI_PROCESS, MODE_NO_LOCALIZED_COLLATORS, MODE_PRIVATE, MODE_WORLD_READABLE, MODE_WORLD_WRITEABLE, NETWORK_STATS_SERVICE, NFC_SERVICE, NOTIFICATION_SERVICE, NSD_SERVICE, POWER_SERVICE, PRINT_SERVICE, RESTRICTIONS_SERVICE, SEARCH_SERVICE, SENSOR_SERVICE, SHORTCUT_SERVICE, STORAGE_SERVICE, SYSTEM_HEALTH_SERVICE, TELECOM_SERVICE, TELEPHONY_SERVICE, TELEPHONY_SUBSCRIPTION_SERVICE, TEXT_SERVICES_MANAGER_SERVICE, TV_INPUT_SERVICE, UI_MODE_SERVICE, USAGE_STATS_SERVICE, USB_SERVICE, USER_SERVICE, VIBRATOR_SERVICE, WALLPAPER_SERVICE, WIFI_P2P_SERVICE, WIFI_SERVICE, WINDOW_SERVICE

Fields inherited from interface android.content.ComponentCallbacks2

TRIM_MEMORY_BACKGROUND, TRIM_MEMORY_COMPLETE, TRIM_MEMORY_MODERATE, TRIM_MEMORY_RUNNING_CRITICAL, TRIM_MEMORY_RUNNING_LOW, TRIM_MEMORY_RUNNING_MODERATE, TRIM_MEMORY_UI_HIDDEN

Constructor Summary

Constructors

Constructor and Description
FittsTouchActivity()

Method Summary

Modifier and Type	Method and Description
void	doFingerDown(float xArg, float yArg)
void	doStartCircleSelected()
void	onCreate(android.os.Bundle savedInstanceState) Called when the activity is first created.
boolean	onTouch(android.view.View v, android.view.MotionEvent me)

Methods inherited from class android.app.Activity

addContentView, closeContextMenu, closeOptionsMenu, createPendingResult, dismissDialog, dismissKeyboardShortcutsHelper, dispatchGenericMotionEvent, dispatchKeyEvent, dispatchKeyShortcutEvent, dispatchPopulateAccessibilityEvent, dispatchTouchEvent, dispatchTrackballEvent, dump, enterPictureInPictureMode, findViewById, finish, finishActivity, finishActivityFromChild, finishAffinity, finishAfterTransition, finishAndRemoveTask, finishFromChild, getActionBar, getApplication, getCallingActivity, getCallingPackage, getChangingConfigurations, getComponentName, getContentScene, getContentTransitionManager, getCurrentFocus, getFragmentManager, getIntent, getLastNonConfigurationInstance, getLayoutInflater, getLoaderManager, getLocalClassName, getMediaController, getMenuInflater, getParent, getParentActivityIntent, getPreferences, getReferrer, getRequestedOrientation, getSearchEvent, getSystemService, getTaskId, getTitle, getTitleColor, getVoiceInteractor, getVolumeControlStream, getWindow, getWindowManager, hasWindowFocus, invalidateOptionsMenu, isChangingConfigurations, isChild, isDestroyed, isFinishing, isImmersive, isInMultiWindowMode, isInPictureInPictureMode, isLocalVoiceInteractionSupported, isTaskRoot, isVoiceInteraction, isVoiceInteractionRoot, managedQuery, moveTaskToBack, navigateUpTo, navigateUpToFromChild, onActionModeFinished, onActionModeStarted, onActivityReenter, onActivityResult, onApplyThemeResource, onAttachedToWindow, onAttachFragment, onBackPressed, onChildTitleChanged, onConfigurationChanged, onContentChanged, onContextItemSelected, onContextMenuClosed, onCreate, onCreateContextMenu, onCreateDescription, onCreateDialog, onCreateDialog, onCreateNavigateUpTaskStack, onCreateOptionsMenu, onCreatePanelMenu, onCreatePanelView, onCreateThumbnail, onCreateView, onCreateView, onDestroy, onDetachedFromWindow, onEnterAnimationComplete, onGenericMotionEvent, onKeyDown, onKeyLongPress, onKeyMultiple, onKeyShortcut, onKeyUp, onLocalVoiceInteractionStarted, onLocalVoiceInteractionStopped, onLowMemory, onMenuItemSelected, onMenuOpened, onMultiWindowModeChanged, onNavigateUp, onNavigateUpFromChild, onNewIntent, onOptionsItemSelected, onOptionsMenuClosed, onPanelClosed, onPause, onPictureInPictureModeChanged, onPostCreate, onPostCreate, onPostResume, onPrepareDialog, onPrepareDialog, onPrepareNavigateUpTaskStack, onPrepareOptionsMenu, onPreparePanel, onProvideAssistContent, onProvideAssistData, onProvideKeyboardShortcuts, onProvideReferrer, onRequestPermissionsResult, onRestart, onRestoreInstanceState, onRestoreInstanceState, onResume, onRetainNonConfigurationInstance, onSaveInstanceState, onSaveInstanceState, onSearchRequested, onSearchRequested, onStart, onStateNotSaved, onStop, onTitleChanged, onTouchEvent, onTrackballEvent, onTrimMemory, onUserInteraction, onUserLeaveHint, onVisibleBehindCanceled, onWindowAttributesChanged, onWindowFocusChanged, onWindowStartingActionMode, onWindowStartingActionMode, openContextMenu, openOptionsMenu, overridePendingTransition, postponeEnterTransition, recreate, registerForContextMenu, releaseInstance, removeDialog, reportFullyDrawn, requestDragAndDropPermissions, requestPermissions, requestShowKeyboardShortcuts, requestVisibleBehind, requestWindowFeature, runOnUiThread, setActionBar, setContentTransitionManager, setContentView, setContentView, setContentView, setDefaultKeyMode, setEnterSharedElementCallback, setExitSharedElementCallback, setFeatureDrawable, setFeatureDrawableAlpha, setFeatureDrawableResource, setFeatureDrawableUri, setFinishOnTouchOutside, setImmersive, setIntent, setMediaController, setProgress, setProgressBarIndeterminate, setProgressBarIndeterminateVisibility, setProgressBarVisibility, setRequestedOrientation, setResult, setResult, setSecondaryProgress, setTaskDescription, setTheme, setTitle, setTitle, setTitleColor, setVisible, setVolumeControlStream, setVrModeEnabled, shouldShowRequestPermissionRationale, shouldUpRecreateTask, showAssist, showDialog, showDialog, showLockTaskEscapeMessage, startActionMode, startActionMode, startActivities, startActivities, startActivity, startActivity, startActivityForResult, startActivityForResult, startActivityFromChild, startActivityFromChild, startActivityFromFragment, startActivityFromFragment, startActivityIfNeeded, startActivityIfNeeded, startIntentSender, startIntentSender, startIntentSenderForResult, startIntentSenderForResult, startIntentSenderFromChild, startIntentSenderFromChild, startLocalVoiceInteraction, startLockTask, startManagingCursor, startNextMatchingActivity, startNextMatchingActivity, startPostponedEnterTransition, startSearch, stopLocalVoiceInteraction, stopLockTask, stopManagingCursor, takeKeyEvents, triggerSearch, unregisterForContextMenu

Methods inherited from class android.view.ContextThemeWrapper

applyOverrideConfiguration, attachBaseContext, getAssets, getResources, getTheme

Methods inherited from class android.content.ContextWrapper

bindService, checkCallingOrSelfPermission, checkCallingOrSelfUriPermission, checkCallingPermission, checkCallingUriPermission, checkPermission, checkSelfPermission, checkUriPermission, checkUriPermission, clearWallpaper, createConfigurationContext, createDeviceProtectedStorageContext, createDisplayContext, createPackageContext, databaseList, deleteDatabase, deleteFile, deleteSharedPreferences, enforceCallingOrSelfPermission, enforceCallingOrSelfUriPermission, enforceCallingPermission, enforceCallingUriPermission, enforcePermission, enforceUriPermission, enforceUriPermission, fileList, getApplicationContext, getApplicationInfo, getBaseContext, getCacheDir, getClassLoader, getCodeCacheDir, getContentResolver, getDatabasePath, getDataDir, getDir, getExternalCacheDir, getExternalCacheDirs, getExternalFilesDir, getExternalFilesDirs, getExternalMediaDirs, getFilesDir, getFileStreamPath, getMainLooper, getNoBackupFilesDir, getObbDir, getObbDirs, getPackageCodePath, getPackageManager, getPackageName, getPackageResourcePath, getSharedPreferences, getSystemServiceName, getWallpaper, getWallpaperDesiredMinimumHeight, getWallpaperDesiredMinimumWidth, grantUriPermission, isDeviceProtectedStorage, isRestricted, moveDatabaseFrom, moveSharedPreferencesFrom, openFileInput, openFileOutput, openOrCreateDatabase, openOrCreateDatabase, peekWallpaper, registerReceiver, registerReceiver, removeStickyBroadcast, removeStickyBroadcastAsUser, revokeUriPermission, sendBroadcast, sendBroadcast, sendBroadcastAsUser, sendBroadcastAsUser, sendOrderedBroadcast, sendOrderedBroadcast, sendOrderedBroadcastAsUser, sendStickyBroadcast, sendStickyBroadcastAsUser, sendStickyOrderedBroadcast, sendStickyOrderedBroadcastAsUser, setWallpaper, setWallpaper, startInstrumentation, startService, stopService, unbindService, unregisterReceiver

Methods inherited from class android.content.Context

getColor, getColorStateList, getDrawable, getString, getString, getSystemService, getText, obtainStyledAttributes, obtainStyledAttributes, obtainStyledAttributes, obtainStyledAttributes, registerComponentCallbacks, unregisterComponentCallbacks

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FittsTouchActivity

public FittsTouchActivity()

Method Detail

onCreate

public void onCreate(android.os.Bundle savedInstanceState)

Called when the activity is first created.

Overrides:

onCreate in class android.app.Activity

onTouch

public boolean onTouch(android.view.View v,
                       android.view.MotionEvent me)

Specified by:

onTouch in interface android.view.View.OnTouchListener

doFingerDown

public void doFingerDown(float xArg,
                         float yArg)

doStartCircleSelected

public void doStartCircleSelected()