ca.yorku.cse.mack.fittstilt

Class FittsTiltActivity

java.lang.Object

android.content.Context

android.content.ContextWrapper

android.view.ContextThemeWrapper

android.app.Activity

ca.yorku.cse.mack.fittstilt.FittsTiltActivity

All Implemented Interfaces:

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

public class FittsTiltActivity
extends android.app.Activity
implements android.hardware.SensorEventListener

FittsTilt

Summary

• Android experiment software for Fitts' law target acquisition using device tilt

• Implements the two-dimensional (2D) Fitts' law task 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.

• "FittsTilt: The Application of Fitts' Law to Tilt-based Interaction", by MacKenzie and Teather (NordiCHI 2012).

• "Position vs. Velocity Control for Tilt-based Interaction", by Teather and MacKenzie (Graphics Interface 2014).

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

• "Towards a Standard for Pointing Device Evaluation: 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:

In all, there are 14 setup parameters organized as 12 spinners and two checkboxes. 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).
Number of targets	Specifies the number of targets that appear in the layout circle.
Target amplitude (A)	Specifies the diameter of the layout circle. The spinner offers three choices: "150, 250, 500", "250, 500", or "500" (but see note 2 below).
Target width (W)	Specifies the width of targets. This is the diameter of the target circles. The spinner offers three choices: "40, 60, 100", "60, 100", 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.
Ball scale	A scaling factor from the set { 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 }. The diameter of the virtual ball is adjusted to be the diameter of the smallest target times this scaling factor.
Order of control	The options are Velocity – tilting the device controls the velocity of the virtual ball Position – tilting the device controls the position of the virtual ball
Tilt gain	A value from the set { Very low, Low, Medium, High, Very high } roughly corresponding to gain sensitivities ranging for very low to very high.
Selection mode	The options are First_entry – a target is selected as soon as the virtual ball is fully inside the target Dwell_500 – a target is selected after the virtual ball is fully inside the target for 500 ms Dwell_400 – a target is selected after the virtual ball is fully inside the target for 400 ms Dwell_300 – a target is selected after the virtual ball is fully inside the target for 300 ms
Vibrotactile feedback	A checkbox parameter. If checked, a vibrotactile pulse is emitted upon each target selection.
Audio feedback	A checkbox parameter. If checked, an auditory beep is heard upon each target selection.

Operation

Once the setup parameters are chosen, the testing begins by tapping "OK". The first screen to appear is a transition screen. See below. The transition screen provides two options. To select an option the user must manoeuvre the virtual ball to the green or blue circle and dwell on the circle for one second. If the green circle is selected, the user has the opportunity to do a sequence of practice trials. No data are saved for practice trials. If the blue circle is selected, the application transitions to the first sequence of experiment trials.

A series of trials for a single A-W condition is called a "sequence". The target to select is highlighted in pink (below, left). After a selection, the highlight moves to a target on the opposite side of the layout circle. The pattern of selecting moves around the layout circle until all targets are selected. At the end of a sequence, results appear on the display (below, right).

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

Output Data Files

For each block of testing, three output data files are created: sd1, sd2, and sd3. ("sd" is for "summary data".) The sd1 file contains data for each trial of input. The sd2 file contains data summarizing each sequence of trials. The sd3 file contains trace data for each trial, including x, y, and tilt angle for each sample. A separate utility called FittsTiltTrace is available to plot the data in the sd3 files. The following are examples of the summary data files:

• sd1 – FittsTilt-P03-S01-B01-G01-C01-POS-TG20-FIRST_ENTRY.sd1
• sd2 – FittsTilt-P03-S01-B01-G01-C01-POS-TG20-FIRST_ENTRY.sd2
• sd3 – FittsTilt-P03-S01-B01-G01-C01-POS-TG20-FIRST_ENTRY.sd3

For most analyses, the data in the sd2 files are sufficient. The data are comma delimited for easy importing into Excel or a statistics application for follow-up analyses. An example is shown below for the data in the sd2 file above.

Author:

Scott MacKenzie, 2011-2016

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	FittsTiltActivity.ScreenRefreshTimer

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
FittsTiltActivity()

Method Summary

Modifier and Type	Method and Description
int	getDefaultDeviceOrientation()
protected float[]	lowPass(float[] input, float[] output, float alpha)
void	onAccuracyChanged(android.hardware.Sensor sensor, int accuracy)
void	onCreate(android.os.Bundle savedInstanceState) Called when the activity is first created.
protected void	onPause()
protected void	onResume()
void	onSensorChanged(android.hardware.SensorEvent se)
void	onWindowFocusChanged(boolean hasFocus)

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, onPictureInPictureModeChanged, onPostCreate, onPostCreate, onPostResume, onPrepareDialog, onPrepareDialog, onPrepareNavigateUpTaskStack, onPrepareOptionsMenu, onPreparePanel, onProvideAssistContent, onProvideAssistData, onProvideKeyboardShortcuts, onProvideReferrer, onRequestPermissionsResult, onRestart, onRestoreInstanceState, onRestoreInstanceState, onRetainNonConfigurationInstance, onSaveInstanceState, onSaveInstanceState, onSearchRequested, onSearchRequested, onStart, onStateNotSaved, onStop, onTitleChanged, onTouchEvent, onTrackballEvent, onTrimMemory, onUserInteraction, onUserLeaveHint, onVisibleBehindCanceled, onWindowAttributesChanged, 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

FittsTiltActivity

public FittsTiltActivity()

Method Detail

onCreate

public void onCreate(android.os.Bundle savedInstanceState)

Called when the activity is first created.

Overrides:

onCreate in class android.app.Activity

onWindowFocusChanged

public void onWindowFocusChanged(boolean hasFocus)

Specified by:

onWindowFocusChanged in interface android.view.Window.Callback

Overrides:

onWindowFocusChanged in class android.app.Activity

getDefaultDeviceOrientation

public int getDefaultDeviceOrientation()

onResume

protected void onResume()

Overrides:

onResume in class android.app.Activity

onPause

protected void onPause()

Overrides:

onPause in class android.app.Activity

onAccuracyChanged

public void onAccuracyChanged(android.hardware.Sensor sensor,
                              int accuracy)

Specified by:

onAccuracyChanged in interface android.hardware.SensorEventListener

onSensorChanged

public void onSensorChanged(android.hardware.SensorEvent se)

Specified by:

onSensorChanged in interface android.hardware.SensorEventListener

lowPass

protected float[] lowPass(float[] input,
                          float[] output,
                          float alpha)