Danielle Daidone
  • Home
  • Research
    • Publications
    • Current Research Projects
  • Teaching
  • Praat Scripts
  • Resources & Links
  • Blog

Coding a free classification task

3/12/2022

0 Comments

 
Once you have results for your free classification task, you'll need to code what stimuli participants grouped together.  We recommend having around 30 participants or more for your eventual analysis.  If you use the format pictured below, you will then be able to use an R script that creates similarity matrices from your data.
Picture
Make sure you label your columns this way so that the R script will work correctly.
Subject: The participant's ID 
Version: The version of the task that the participant did
  • For example, in our Finnish length task we had two versions for the different orders of slides that we counterbalanced.  In version A, the "ata" context (pata, paata, patta, etc.) was on slide 1, the "iki" context (tiki, tiiki, tikki, etc.) was on slide 2, and the "upu" context (kupu, kuupu, kuppu, etc.) was on slide 3.  In version B, the "upu" context was first, the "iki" context was second, and the "ata" context was third.  Be sure to use the letters "A" and "B" for your coding instead of numbers.  If you only have one version, label them all version A.  You'll still need this column for the R code.  If you have more than 2 versions, the R code won't work.  Send me an email and I can modify the script for you.
Slide: The slide that you are coding
Context: The context for that slide
Group: Which group on that slide you are coding
Tokens: Which tokens were grouped together
 in that group
Let's use the following participant's results as a model.  Here is their first slide:  ​
Picture
This participant's ID is B50.  They did version A of our task.  This is slide 1, and In Version A, the context on the first slide is "ata".  They made 5 groups of stimuli on this slide, so let's choose a group at random and code it, for instance the group at the left containing 19, 14, 23, 20, and 24.  Since this is the first group we're coding on this slide, we can label it group 1 under Group and put in the token numbers under Tokens.  For the token numbers, we want to separate them with commas and no spaces.  It doesn't matter what order the token numbers are in within that cell.  So now we have:
Picture
If we code the rest of the groups on this slide, we have:
Picture
Here is B50's second slide:
Picture
And below is the coding for this slide added to the spreadsheet.  Since B50 made 4 groups on this slide, we only have 1-4 under Group:
Picture
Here is B50's slide 3:
Picture
And the coding for this slide added to the spreadsheet:
Picture
This participant's results are finished being coded!  Do this for all your participants and you'll be ready to analyze your data.  You'll need to save this spreadsheet as a tab-separated text file for use with the R script to create similarity matrices.
0 Comments

Creating a free classification task

3/2/2022

0 Comments

 
In this post I'll discuss how to create a free classification task, also known as a free sort task, which we apply to non-native perception in Daidone, Kruger, and Lidster (2015).  This task is useful for determining the perceptual similarity of non-native sounds and examining what acoustic, phonological, or indexical dimensions of the stimuli matter for listeners.  It can be used to examine segmental or suprasegmental phenomena and can be used to predict their discriminability (check out our slides from New Sounds 2019).  Here is an example of what our Finnish length free classification task looks like in PowerPoint.  The numbers on the slide are sound files that participants click on and listen to and then group by which seem similar to them.
Picture

Read More
0 Comments

Cutting sound files

2/6/2019

0 Comments

 
Once you have the sound file containing all of your stimuli, you'll need to segment it into smaller, individual files for each stimulus.  You can do this using the free acoustic analysis software Praat, available at praat.org.

Once you open Praat, you'll see that both a "Praat Objects" window and a "Praat Picture" window appear at start up.  You won't be using the Praat picture window, so you can close that.

Before we begin cutting a sound file, let's just see what sounds look like in Praat.  In the top menu, go to "Open" --> "Read from file" and choose your sound file.  It should now appear highlighted in the Objects window.  Click on "View & Edit" on the right-hand menu to see your sound file:

Read More
0 Comments

Tips for recording stimuli

8/3/2017

0 Comments

 
The recording list:
  • Make sure it's easy to read for the speakers (i.e. the font is 12pt or bigger).  I like to use 3 double-spaced columns per page.  You could also number the words.  
  • If the list is long (more than 2 pages), number the pages to avoid confusion and add titles for each part of the list (stimuli for AX, stimuli for lexical decision).  If they read the titles, this could help you later when cutting the sound files.
  • Oftentimes the last word of a list is said with different intonation (a final fall); repeat this word earlier in the list or at least have it be a filler.
  • Print the recording list one sided, or make sure they don't turn the page while speaking, since this will be audible.    

Read More
0 Comments

Creating stimuli

7/11/2017

0 Comments

 
Once you've chosen a perception task, it's time to make stimuli for it.  

How many stimuli do I need?
The answer to this question isn't simple.  You'll need to strike a balance between getting a sufficient amount of data and how long you can reasonably expect people to sit and do your experiment.  In our lab, we generally have to recruit participants with extra credit, the promise of snacks, and desperate pleas, so any experiment over an hour or an hour and 15 minutes is unlikely to have many people sign up.  If you can pay people they'll be more willing to do a longer experiment, but that means more money you'll have to shell out for each person.  Since your experiment is likely to be made up of two or more tasks, such as both discrimination and lexical decision plus a background questionnaire, each task in itself shouldn't be longer than about 25 minutes, if possible.  Shorter tasks will also prevent participants' attention from wandering too much, which means more reliable data.  A 20-minute AXB or oddity task is already very boring even with a break, and with difficult contrasts it can also be mentally taxing and demoralizing.  I know some psychology experiments have participants doing one repetitive task for an hour (how?!), but if you don't want participants to constantly time out on trials because they are falling asleep or trying to surreptitiously check their phones, keep it shorter. ​
​

Read More
0 Comments

Choosing a perception task

6/9/2017

0 Comments

 
Welcome to my blog!  I've decided to use this space as a how-to for creating and running perception experiments, both as a way to organize my thoughts and as a way to help you, random person on the internet.  I'm writing this for an audience (assuming you exist) that has some knowledge of L2 phonology, but no practical experience running experiments.  

So let's get started!  First of all, if you're excited to start a perception experiment, as we all should be, you have a research question in mind that you want answered.  This research question will determine what kind of task you should use, as different types of tasks examine different levels of processing.  In this post I'll outline common types of research questions along with their corresponding appropriate task(s).
​


Read More
0 Comments

    Author

    I like sounds.  Here I'll teach you how to play with them and force other people to listen to them.  For science.

    Archives

    March 2022
    February 2019
    August 2017
    July 2017
    June 2017

    Categories

    All
    Creating Perception Tasks
    Free Classification

    RSS Feed

Copyright © 2022
​Danielle Daidone
​daidoned AT uncw DOT edu
You can also check out my Academia.edu and ResearchGate pages
  • Home
  • Research
    • Publications
    • Current Research Projects
  • Teaching
  • Praat Scripts
  • Resources & Links
  • Blog