MuSSeL file names include the student ID and a file number separated by an “_.” The student ID consists of 11 characters and specifies students’ language, unique ID, age group, and the overall assigned rating on the ACTFL test. The file number counts each student’s produced speech files. Each student usually has multiple speech files. For example, file c0002cadr01_1 means that the speaker is a Chinese adult learner with an ILR rating of 1.

Other character combinations or codes in file names:

Character 1: Language

c for Chinese, f for French, p for Portuguese, r for Russian, and s for Spanish.

Characters 7 & 8: Context or Learner age group

• “ad” marks adult students.
• If the learner is a child, a 2-digit code indicates child’s grade level (i.e., 03, 04, 05, 06, 07, 08, 09, 10).

Characters 10 & 11: Rating

Child Ratings

• “ba” means child rating below N1. “b” stands for below, and “a” stands for Form “A” in the AAPPL test. N1 is the lowest rating possible when a student takes Form A of the AAPPL test and the AAPPL rating, “below N1”, means that raters were unable to rate the speaker’s performance based on the ACTFL rating scale.
• "bb" means child rating below N4. The first “b” stands for below, and the second “b” stands for Form “B” in the AAPPL test. N4 is the lowest rating possible when a student takes Form B of the AAPPL test and the AAPPL rating, “below N4” means that the student took Form B of the AAPPL test and raters were unable to assign a rating to the speaker since the performance was below the lowest rating possible.
• "aa" marks an Advanced child rating. The character “a” was repeated to achieve consistency in file name length.
• Other child rating codes are n1, n2, n3, n4, i1, i2, i3, i4, i5.

Adult Ratings

• “00”, “01”, “02”, “03” represent adult ratings, 0, 1, 2, and 3 (ILR rating scale for the OPIc Test), respectively.
• “0p”, “1p”, “2p” correspond to adult ratings, 0+, 1+, and 2+ (ILR rating scale for the OPIc Test), respectively.
• “aa” specifies the adult rating, AL-AH. This rating is given when the rater cannot choose a specific sub-level (Low, Medium, High) under the Advanced level.
• "ss" marks adult rating, S or superior.
• Other adult rating codes are nl, nm, nh, il, im, ih, al, am, ah.

When a file number is missing from the database, it could mean one of the following:

• The file was EMPTY or fully unintelligible.
• The file was corrupt, and wouldn’t open, so we were unable to transcribe it. (Rare case)

The MP3 file is the original speech file produced on the test by the speaker. The MP3 files were transcribed according to the 2021 CHAT transcription protocols established by CHILDES (MacWhinney, 2000). CHA files are the transcriptions written in CLAN. Including CHA files allows the users to enjoy the multitude of tools for tagging and linguistics analyses available on the CLAN program. The TXT file is a copy of the transcriptions in CHA format with a few modifications: 1) angle brackets have surrounded the TXT file headers to separate the headers from the main text and allow the analysis of the main text in corpus analysis tools, 2) the bullets or time stamps that link the audio files to the CHA files have been removed since they have no use in TXT files. TXT files may be used by corpus users who are unfamiliar with the CLAN program or prefer to use other corpus analysis tools. Finally, the PDF file format allows the users to preview the files in their browsers before downloading them. Including the additional formats improves overall accessibility for MuSSeL.

Gender data was not collected from adult speakers in the past few years. Most recent adult data usually include gender information.

The adult files in MuSSeL come from the Oral Proficiency Interview by Computer (OPIc) tests. “An OPIc can be rated according to the ACTFL scale, the Interagency Language Roundtable (ILR) scale, or the Common European Framework of Reference for Languages (CEFR) scale (Language Testing International, n.d.). In MuSSeL, the adult files either had the ACTFL rating or the ILR rating. “An ACTFL OPIc reports a rating between Novice and Superior on the ACTFL scale. An ILR OPIc rating reported is between ILR 0 (No Proficiency) and ILR 3 (Professional Proficiency)” (Language Testing International, n.d.). The following table demonstrates the correspondence between ACTFL and CEFR ratings on OPIc tests.

ACTFL and CEFR Rating Alignment on OPIc(adapted from the ACTFL report, Assigning CEFR Ratings to ACTFL Assessments)

As for the ILR rating scale, we have not provided the corresponding CEFR or ACTFL ratings since there is no consensus in the literature on the alignment between the ILR-scaled score (0, 0+, 1, 1+, 2, 2+, 3) and the other two scales.

AAPPL Rating Alignment with ACTFL and CEFR Scales (ACTFL Proficiency Guidelines, 2012)

List of topics in MuSSeL were created in five steps: 1) transcribers identified the subjects of the speech files and added annotations to the transcription files, 2) all topics were collected from the files and the database spreadsheets and ordered based on frequency, 3) topics with lower frequency were merged into broader categories, 4) the list of topics under each broad category was recorded and reshared with the transcribers, 5) the assigned topics were revised on the database spreadsheet to match the finalized list of topics. The following are lists of topics that emerged from the child and adult sub-corpora.

List of Topics in the Child Sub-Corpus

1. About Yourself
2. Activities
3. Clothes
4. Colors
5. Current Affairs
6. Family
7. Food
8. Holidays
9. Introductions
10. Locations
11. Other People
12. Routines
13. School
14. Sports
15. Time, Seasons, Climate
16. Unspecified (Unable to Specify a Topic, Unintelligible Content)

List of Topics in the Adult Sub-Corpus

1. About Yourself
2. Business & Technology
3. Current affairs
4. Education
5. Entertainment
6. Events & Activities
7. Family
8. Food
9. Jobs
10. Locations
11. People
12. Questions
13. Routines
14. Sports
15. Travel
16. Unspecified (Unable to Specify a Topic, Unintelligible content)