GeoTalk: a GPS-Enabled Portable Speech Output Device for People with Intellectual Disability

  • Daniel K. Davies
  • Steven E. Stock
  • Richard G. Herold
  • Michael L. Wehmeyer
ORIGINAL PAPER
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Abstract

A high percentage of people with intellectual disability experience communication impairments that limit their use of spoken language and make the use of alternative and augmentative communication (AAC) devices potentially beneficial. However, AAC devices often present barriers for people with intellectual disability due to the complexity of switching between levels and overlays and by hardware configurations that limit the number of words or phrases that can be programmed into a device. This study reports on an evaluation of GeoTalk, a handheld device application that incorporates universal design in the user interface and integrates global positioning system (GPS), electronic schedule timers, and other sensor technology to automatically switch between vocabulary sets when the user enters a designated geographic zone, such as a school, bank, and grocery store. The system also triggers automated switches in vocabulary sets based upon time of day or remote sensors in situations that require a unique vocabulary set. Findings from the pilot test showed that people with intellectual disability were able to operate the GPS-enabled GeoTalk device with fewer errors, requiring fewer prompts, and with greater speed than two commercially available comparison AAC devices.

Keywords

Alternative and augmentative communication GeoTalk Intellectual disability 

Achieving increased independence for people with intellectual disability is a high priority goal in most service and support systems and among family members. One frequent barrier to achieving this goal involves communication-related requirements associated with living, working, learning, or playing more independently. A high percentage of people with intellectual disability experience communication impairments, and some people benefit from alternative and augmentative communication (AAC) devices as a means to overcome communication barriers associated with greater independence (Mirenda and Mathy-Laikko 1989).

Unfortunately, the complexity of many synthesized speech AAC devices presents significant barriers to independent use (Light and McNaughton 2015). Such devices often have a large number of buttons, leveled or vocabulary set approaches that allow the system to be reconfigured so that each button can have several different voice output words or phrases programmed at each level. For example, the first level may include a number of vocabulary entries related to home use, level two could be work vocalizations, level three could include restaurant ordering phrases, and so forth. As levels are changed, so must the pictures and text (if provided) on each button so that they coincide with the new vocalizations at each level and remain intuitive. This is sometimes accomplished by sliding a new “overlay” card into the unit that covers the buttons and effectively changes the pictures and/or text on each button. When a new overlay card is inserted, the system must also be electronically reconfigured so that new voice output messages play to match the new overlay pictures. Therefore, each level in a system has a corresponding overlay card and vocabulary set that must also be changed out when changing levels. Other devices change levels via onscreen or hardware navigation buttons and sometimes complex menu systems. Such leveling interfaces can present a significant barrier to AAC device use by many people with intellectual disability.

Tablet and mobile technologies provide digital solutions to these barriers, among other benefits. McNaughton and Light (2013) noted that such tools have the additional benefit of increasing social acceptance of AAC use, enhancing the empowerment of AAC users, higher levels of adoption, and enhanced flexibility in functionality and connectivity. Global positioning system (GPS)-enabled devices provide additional benefits in their flexibility and potential utility for community inclusion. Williamson, Aplin, de Jonge, and Goyne (2017) showed that wearable GPS devices were both socially acceptable and effective in ensuring safety of people who were elderly or aging or with a disability. Davies, Stock, Holloway, and Wehmeyer (2010) showed that a GPS-based transportation support device improved independent bus use by people with intellectual disability. The so-called “context aware” technologies that utilize GPS data to activate potential communication templates related to the person’s location (as determined by the GPS capacity of the communication device) have considerable potential to overcome barriers pertaining to complexity in device use, such as the issue of layering.

The purpose of the present study was to test the feasibility of a device that combined GPS information with the capacity of an AAC device to provide geolocation-aware word/phrase options. This device, called GeoTalk, was compared with two devices that were significantly different in design approaches but were frequently used by people with intellectual disability. All three AAC devices used in the study were populated with the exact same vocabulary content, including the same categories, pictures, and speech output phrases. The GeoTalk and one of the comparison systems also supported an access feature that cued the user to the selected vocabulary set with a system audio file (e.g., “Here are your things to say at school”), and these cues were also identical.

Method

Participants

Study participants were students and adults with intellectual disability who were learning community-inclusion skills with support from multiple service-providing agencies. Most participants had some degree of speech impairment, although this was not a criterion for participation as this was a technology usability study focused on cognitive accessibility issues. A total of 37 people participated in the study, 22 of whom were male and 15 individuals who were female. The average age of participants was 31.05 (SD = 10.68), ranging from 18 to 55 years of age. The average WIAS-R IQ score, obtained from existing records, was 53.2 (SD = 10.45) with a range from 32 to 70. All participants in this project were at least 18 years of age and were their own guardians. The informed consent process was followed on all participants per approved IRB requirements. Participant involvement was entirely voluntary, and participants received a non-contingent cash stipend for their time during the study.

Procedure

Device

The prototype app was developed on a GPS-enabled Pharos 535 Pocket PC unit using Microsoft’s Visual Studio .NET Compact Framework system and C#. The system was configured with four designated GPS waypoints for each of the four vocabulary sets. The range available for the GPS signal was a diameter of 50 ft, so that when the user moved to within 25 ft of the waypoint, the vocabulary set change was activated. Once the user entered into one of the designated GPS zones, GeoTalk produced a customizable distinctive alarm (e.g., cow bell) and automatically loaded a full-screen display which served as a cue to the user that a GPS communication zone had been entered. Figure 1 shows GeoTalk after being activated in two different GPS communication zones used in the study.
Fig. 1

Sample GeoTalk screens before receiving GPS signal

When the GeoTalk unit entered into a GPS communication zone, both the alarm and the full-screen display (as shown in Fig. 1) served as a cue to the user that a communication zone had been entered and the unit was ready for use. At this point, when the user tapped anywhere on the full-screen image, a corresponding audio cue provided confirmation of the vocabulary set being loaded, such as Here are your things to say at school or “Here are your things to say at the restaurant.” At the same time, the category image shown in Fig. 1 was replaced with the corresponding vocabulary set for that location, such as those shown in Fig. 2.
Fig. 2

GeoTalk screen displaying communication content after tapping category image (L-school vocabulary; R-work vocabulary)

At this point, the GeoTalk system was ready for communication. Therefore, to change vocabulary sets in GeoTalk, the user simply walked to the appropriate location and tapped the screen. Once a GPS communication zone had been entered and the category image was displayed such as in Fig. 1, the image remained on the screen until it was (1) tapped to activate the corresponding vocabulary set or (2) the user traveled to a different GPS communication zone. In the latter case, the system continued to display the image for the previous GPS communication zone even after the user moved out of range of the zone, until the user moved into a new GPS communication zone. This allowed the user to retain access to the previous vocabulary set while traveling to the next GPS communication zone.

Finally, when the user selected an individual button to initiate a speech output phrase, GeoTalk played a digital recording of the appropriate phrase while displaying the selected button full screen, as shown in the Fig. 3 examples. This feature was developed to provide a level of confirmation to the user that the intended button was successfully selected and allowed the user to show the image to his or her communication partner to support the audio output, if desired.
Fig. 3

GeoTalk phrase samples: “I need to sharpen my pencil,” “Is it almost lunch time?”, “When do I get my pay check?” and “I need to call my mom”

The speaker icon near the top/right of the screen in Fig.2 is used to change the volume or mute the system. Tapping on the speaker icon consecutively increased the volume incrementally to the point of maximum volume. At that point, an additional tap muted the volume all together, and further taps repeated the cycle. This feature was developed to provide independent access to the volume control by individuals with intellectual disabilities, as it was just large enough for users to tap with a fingernail but small enough to deter accidental access. A final element on the top of the GeoTalk displays shown in Fig.2 involves a series of vertical bars which depicted the relative strength of the GPS signal being received at any particular time. Signal strength indicated by a minimum of one bar was necessary for GeoTalk to work, and the strongest signal attainable was represented by five bars as shown in the leftmost picture in Fig.2.

Study Design

The study utilized a three group within subjects design (Campbell and Stanley 1963). There was one independent variable with three levels: (1) use of the comparison AAC #1, (2) use of comparison AAC #2, and (3) use of the GeoTalk AAC device. The dependent variables were (1) instances of prompts required to communicate at different locations (bus stop, work, restaurant, and school); (2) training effectiveness as measured by accuracy/number of errors made in completing communication tasks; and (3) time required to complete each step in the communication task sequence. The order of the experimental conditions and communication task sequences were both randomized to control for order effects.

The GeoTalk AAC device was compared with two commercially available AAC devices, because they are widely available and frequently used by people with intellectual disability. The first comparison device provided up to nine vocabulary entries in a set, each represented by an image and text in physically separated, touchable areas that are 1 1/2″ × 2″ in size. The device is 8 ½ × 11 in. and about 1-in thick. To operate the unit, the user presses anywhere in the desired button area. To change levels, the user slides out the picture overlay, locates the desired overlay and slides it in the slot on the right side of the unit, and then uses a single round button near the top of the unit to change the audio output to the corresponding vocabulary set. A series of numbered LEDs lights up consecutively as this button is repeatedly pressed until the light next to the desired vocabulary set number is lit. To facilitate the process of level changing during the study, the correct number for an audio vocabulary set was printed on its corresponding overlay card. This allowed users to easily view the number and then toggle the single round button until the correct LED was lit. The up and down arrow buttons at the top right of the unit provided volume controls.

The second comparison AAC device was a palmtop computer-based AAC system that was configured for the study with its simplest interface options for ease of use. To operate the unit, one of the images on the screen is tapped to activate that particular category. A cue also plays announcing the category, such as Here are your things to say at school. The unit then displayed the same eight icon images used in the GeoTalk and first comparison AAC devices. An arrow button is available on each vocabulary set page in the second comparison AAC device to return to the main display. Figures 4,5, 6, and 7 show each of the image sets used by each of the three devices. Figure 4 shows the image set for use at the bus stop, Fig. 5 the image set for use at work, Fig. 6 the image set for use at a restaurant, and Fig. 7 the image set for school.
Fig. 4

Vocabulary set 1-bus stop

Fig.5

Vocabulary set 2-work

Fig. 6

Vocabulary set 3-restaurant

Fig. 7

Vocabulary set 4-school

Each participant engaged with all three AAC systems. To minimize safety risks for purposes of this pilot study, four outdoor locations were identified around the location of the support agencies and were labeled with large signs that included a picture and text designating the site: the bus stop location was at a light post on a university campus; the work location was the front door of a building; the restaurant was at the front door of a second building, and the school location was the front door of a third building. Additionally, three communication sequences were developed, each requiring the participant to activate six speech outputs that each required a vocabulary set change. Table 1 details these three communication sequences.
Table 1

Communication task sequences

Sequence A

Sequence B

Sequence C

1.a Go to BUS STOP Messages

1.a Go to WORK Messages

1.a Go to SCHOOL Messages

1.b Touch the picture that says: Is this bus number 27?

1.b Touch the picture that says: When do I get may paycheck?

1.b Touch the picture that says: I need to call home

2.a Go to SCHOOL Messages

2.a Go To RESTAURANT Msgs

2.a Go to WORK Messages

2.b Touch the picture that says: I need to call home

2.b Touch the picture that says: May I have a fork?

2.b Touch the picture that says: When do I get may paycheck?

3.a Go to WORK Messages

3.a Go to BUS STOP Messages

3.a GO TO RESTAURANT Msgs

3.b Touch the picture that says: When do I get may paycheck?

3.b Touch the picture that says: Is this bus number 27?

3.b Touch the picture that says: May I have a fork?

4.a GO TO RESTAURANT Msgs

4.a Go to SCHOOL Messages

4.a Go to BUS STOP Messages

4.b Touch the picture that says: May I have a fork?

4.b Touch the picture that says: I need to call home

4.b Touch the picture that says: Is this bus 27?

5.a Go to SCHOOL Messages

5.a Go to WORK Messages

5.a Go to SCHOOL Messages

5.b Touch the picture that says: May I sharpen my pencil?

5.b Touch the picture that says: Can I eat my sandwich now?

5.b Touch the picture that says: May I sharpen my pencil?

6.a Go to BUS STOP Messages

6.a Go To RESTAURANT Msgs

6.a Go to WORK Messages

6.b Touch the picture that says: Can you tell me what time it is?

6.b Touch the picture that says: I’d like to order a taco.

6.b Touch the picture that says: Can I eat my sandwich now?

As mentioned previously, both the experimental conditions and the previous task sequences were randomized to control for ordering effect. Test sessions lasted approximately 45–60 min in length. After participants consented to be involved in the project, they were oriented as to the process and purpose of the project. A 5-min training orientation was conducted prior to using each device. These training sessions were scripted for each device and involved a demonstration and hands-on practice of each feature relevant to the study (e.g., changing vocabulary sets, playback of speech output phrases). Researchers then escorted study participants on the route for the designated communication task sequence. Upon completion, the researcher and participant returned to the facility and engaged in another 5-min training session with the next device. Following completion of the subsequent communication task sequence, the process was repeated for the third and final device. Finally, a brief open-ended interview tailored to the abilities of the individual participant was conducted to determine any preferences or feature likes/dislikes.

Measures

Data were collected on the amount of assistance (number of physical or verbal prompts) requested or needed to complete each device’s communication task sequence. To alleviate frustration and to avoid skewing the data, there was a maximum of three prompts per step. If users reached the prompt limit on any given step, the researcher demonstrated the step for the study participant and moved on to the next step. Data were also collected on errors made in completing each communication sequence, which was also limited to a maximum of three per step. Data collectors were trained on the research protocol and use of the data collection instruments and participated in a series of practice trials to identify and correct gaps or inconsistencies in the protocol. Recording both prompts and errors was important to determining the feasibility of the system, as some participants were more hesitant by nature when unsure what to do, and therefore asked for help (i.e., prompts) in lieu of moving ahead and making errors, while other participants who were less inhibited demonstrated more of a trial-and-error approach instead of asking for help when faced with uncertainty. Finally, a stopwatch was used to obtain the time required by each participant to complete the requested communication step. The stopwatch was started at the moment the researcher finished giving the instructions for a step (i.e., “Now we are at the school. Go to the school messages and have it say ‘I need to call my mom’”) and ended when the participant pressed the correct icon on the respective communication device.

Table 2 summarizes the criteria used for scoring each testing session. The performance of each participant was closely monitored, with corrective prompts provided as soon as mistakes were made. In this way, participants always achieved success at the task, even if they needed a great deal of assistance to achieve it, and compounded errors were avoided.
Table 2

Scoring criteria

Errors

An error was recorded (1) if the user did not perform the communication task correctly or (2) if the user skipped the step completely. A maximum of three errors were recorded for each step prior to demonstrating the correct procedure and continuing with the session.

Prompts

A prompt was recorded (1) if the user specifically requested help or (2) if a prompt was provided following an observed error. A maximum of three prompts were recorded for each step prior to demonstrating the correct procedure and continuing with the session.

Time

The time required to complete each communication task was obtained via a stopwatch. Timing began as soon as the researcher completed the instruction for a step, and ended when the participant pressed the correct communication button. If a participant was unable to complete a step and required a demonstration, the time was capped at 1 min which was at the high end of the range of actual time required to complete steps.

Two data collectors scored the subjects in parallel in 46% of the test sessions to measure inter-rater reliability. Inter-rater reliability of ratings for recorded errors was 0.995 and for recorded prompts was 0.985, both significant (p < .01). The ratings made by the two raters were averaged to provide a single score for each dependent variable to support data analysis.

In addition to the quantitative assessments, a series of survey questions was developed and used during an informal post-session interview process. Data recorded during these interviews involved verbatim recording of comments made by participants, which varied from virtually no feedback to more verbose opinions about features and preferences of the three experimental conditions. Given the wide range of the participant’s ability to respond to interview questions and inconsistencies in apparent understanding of questions, these data were not analyzed but did provide anecdotal insight into the device’s usability and desirability by this population.

Data Analyses

The study utilized a within subject multivariate analysis of variance design with three experimental treatment conditions (the GeoTalk system and two commercially available comparison AAC devices). Three communication task sequences (involving the four communication tasks) were developed for the study to present participants with realistic communication activities related to finding, selecting, and playing electronic communication phrases. Each sequence (Table 1) required the same number of changes between vocabulary sets. The resulting data were analyzed using SPSS 16.0, a software package for behavioral statistics. The ANOVA procedure was used to evaluate mean differences between the three experimental conditions (GeoTalk and two comparison AAC devices) for average number of errors, average number of prompts, and seconds to speak.

Results

Table 3 provides descriptive statistics for each AAC device by dependent measure. Analysis of variance yielded significant F statistics for all three dependent variables (average errors, p < .001; average prompts, p < .001; seconds to speak, p < .001) measured in the project study. Table 4 summarizes the results of the ANOVA. Tukey’s HSD post hoc tests are provided in Table 5 and present the mean comparisons for each experimental condition.
Table 3

Descriptive statistics by dependent measure by experimental condition

 

Number

Mean

SD

SE

Min

Max

Average errors

GeoTalk

37

0.61

1.16

0.19095

0

5

Comparison device 1

37

4.17

4.59

0.75492

0

18

Comparison device 2

37

2.93

3.77

0.62004

0

16

Total

111

2.57

3.76

0.35772

0

18

Average prompts

GeoTalk

37

1.09

1.98

0.32641

0

8

Comparison device 1

37

4.95

5.41

0.88984

0

21

Comparison device 2

37

3.70

4.34

0.71436

0

19

Total

111

3.25

4.43

0.42098

0

21.50

Seconds to speak

GeoTalk

37

7.47

6.08

1.00076

2.5

31.17

Comparison device 1

37

34.75

12.00

1.97367

19.5

58.33

Comparison device 2

37

17.71

10.08

1.65746

4.67

42.67

Total

111

19.98

14.84

1.40877

2.5

58.33

Table 4

Analysis of variance results

 

Sum of squares

df

Mean square

F

Sig.

Average errors

Between groups

242.66

2

121.33

9.92

0.000*

Within groups

1319.75

108

12.22

  

Total

1562.42

110

   

Average prompts

Between groups

287.59

2

143.80

8.27

0.000*

Within groups

1876.33

108

17.37

  

Total

2163.93

110

   

Seconds to speak

Between groups

14,050.47

2

7025.23

74.51

0.000*

Within groups

10,181.87

108

94.27

  

Total

24,232.35

110

   

*Statistically significant difference

Table 5

Tukey’s HSD post hoc tests for group differences

Dependent variable

(I) AAC device

(J) Reader

Mean differ

SE

Sig.

Average errors

GeoTalk

Comparison device 1

− 3.56757*

0.81274

0.000*

Comparison device 2

− 2.32432*

0.81274

0.014*

Comparison device 1

GeoTalk

3.56757*

0.81274

0.000*

Comparison device 2

1.24324

0.81274

0.281

Comparison device 2

GeoTalk

2.32432*

0.81274

0.014*

Comparison device 1

− 1.24324

0.81274

0.281

Average prompts

GeoTalk

Comparison device 1

− 3.86486*

0.96908

0.000*

Comparison device 2

− 2.60811*

0.96908

0.022*

Comparison device 1

GeoTalk

3.86486*

0.96908

0.000*

Comparison device 2

1.25676

0.96908

0.400

Comparison device 2

GeoTalk

2.60811*

0.96908

0.022*

Comparison device 1

− 1.25676

0.96908

0.400

Seconds to speak

GeoTalk

Comparison device 1

− 27.27811*

2.25744

0.000*

Comparison device 2

− 10.24162*

2.25744

0.000*

Comparison device 1

GeoTalk

27.27811*

2.25744

0.000*

Comparison device 2

17.03649*

2.25744

0.000*

Comparison device 2

GeoTalk

10.24162*

2.25744

0.000*

Comparison device 1

− 17.03649*

2.25744

0.000*

*Statistically significant difference

Discussion

The results of this pilot evaluation demonstrated the technical merit and feasibility of using GPS technology to support greater independence in the use of communication devices in the community for people with intellectual disability. The study provided evidence to support the hypothesis that the GeoTalk AAC device can be used by people with intellectual disability to access location-based speech output with fewer errors and less assistance than two existing AAC devices commonly recommended for this population.

In fact, when using GeoTalk, nearly 60% (59.4%) of the study participants with intellectual disability were able to complete the prescribed communication tasks with no errors or prompts required. When using the second comparison device, only 19% of the participants were able to complete the study tasks without assistance or errors, and similarly, while using the first comparison device, only 9% of the participants were able to complete the task free of errors and without help. Thus, the GeoTalk prototype was significantly more independently accessible than two leading augmentative communication devices typically used by the target population. The GPS-supported, location-based automated selection of appropriate vocabulary sets successfully supported the independent use of the AAC device in simulated community settings.

Further, interview comments from test subjects with speech abilities indicated a preference for the GeoTalk system (Table 6). Many showed some level of understanding regarding the workings of the GPS feature and appeared to enjoy the experience (see Fig. 6).
Table 6

Comments from participants pertaining to using GeoTalk

“I like that.”

“You press it and it does it itself.”

“It’s not hard to do at all. This is simple. I love computers....man, this is fun. (laughs) I love doing this.”

“If people have a hard time remembering which is which, this is the best. I think this one would be better for the people. They wouldn’t have to worry about changing it themselves. I think the GPS one was better.”

“It’s like magic! It knows I am going to be there, that’s so neat. That’s so neat.” (laughing).

“That’s cool. It tells where it’s at and then what to say. It’s right all the time. I think I like the computer one better.”

“I like the computer one more because it helps you choose.”

“This seems like its way too easy. You just pick the picture.”

“It help me tawk bettow. [sic]”

“Cool, interesting stuff.”

“It can link you to a satellite so you can know what category to select.”

“I like the GPS.”

“It just changed. It knows we’re here. I need one of these.”

“That was fun.”

Limitations, Strengths, and Future Research Directions

There are a number of limitations that must be taken into account when interpreting these findings. First, this study was largely a usability study and not a test of the real-world effectiveness of the GeoTalk approach. It is also the case that given more time to use other systems, participants may have mastered those and differences between their use and the GeoTalk also diminished. Additionally, this study used a relatively small convenience sample without a true control group. Third, although many of the participants had some type or level of communication support needs, the evaluation was not of the efficacy of the device to support communication in the community, but instead of the usability of the device by people with intellectual disability. A full evaluation of the potential usability of AAC devices with GPS capacity to support functional, meaningful communication is needed. Finally, although fidelity was bolstered by the fact that trained personnel from the research group implemented the procedures, a formal fidelity assessment was not conducted, and that should be taken into account.

Despite these limitations, the findings are suggestive of the potential for GPS-enabled, handheld AAC devices to overcome barriers related to device complexity that currently limit the usability of many AAC devices for individuals with intellectual and developmental disabilities. Although the general class of iPad or tablet-based AAC devices should be more flexible in use and address some of the same issues addressed by GeoTalk, issues of cognitive access are not always taken into account, so a next step would be to look at handheld AAC devices to compare usability and flexibility across that common platform. Additionally, future research could compare acquisition of device use across different devices in terms of, for example, trials or speed to mastery and could examine preferred to use after reaching mastery across different devices. Further research and development may also be conducted to expand application of the context-aware approach into settings where GPS signals are not available. For example, several possible methods for supporting automated vocabulary selection may include the use of pre-set timers, Bluetooth, or other sensor-based technologies for automatically initiating context-relevant vocabulary set changes. A schedule-type timing mechanism could be used to program the system based upon a student’s class schedule, so that context appropriate vocabularies could be automatically loaded to meet the speech needs of students while in various classroom settings or even for lunch period. The use of Bluetooth, radio-frequency identification (RFID), or infrared sensors could also be researched to further investigate the automated vocabulary selection approach for indoor situation-specific communication at home, school, or work. Finally, further research may also consider the potential of this approach for other populations such as individuals with significant physical disabilities.

Notes

Author Contributions

DKD and SES: designed and executed the study, assisted with the data analyses, and assisted with writing the paper. RGH: assisted with the data collection and software development. MLW: consulted on research design and assisted with writing the paper.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.

Ethical Approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional committee at the AbleLink Technologies and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed Consent

Informed consent was obtained from all individual participants included in the study.

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Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • Daniel K. Davies
    • 1
  • Steven E. Stock
    • 1
  • Richard G. Herold
    • 1
  • Michael L. Wehmeyer
    • 2
  1. 1.AbleLink Smart Living TechnologiesColorado SpringsUSA
  2. 2.University of KansasLawrenceUSA

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