The Psychometric Properties for the Test of Perceived Physical Competence for Youths with Visual Impairments

Abstract

Introduction

Limited inquiries exist for perceptions of physical competence for people with visual impairments, since there are no specific, psychometrically tested scales. The purpose of this study was to establish the psychometric properties of the Test of Perceived Physical Competence (TPPC) for individuals with visual impairments aged 9–19 years. Methods: Experts (N = 12) provided feedback for content and face validity. Then, after assessing 179 individuals with visual impairments, McDonald’s Omega, and Confirmatory Factor Analyses were used to evaluate the internal consistency and structure. Finally, results of the TPPC were compared with the Self-Perception Profiles for Children/Adolescents for divergent validity. Results: The standardized root mean square residual result of 0.053 and the Comparative Fit Index result of 0.95 indicated acceptable fit. The percent of variation in each item explained by the factor varied from 44% (item 3) to 63% (item 6). McDonald’s Omega for the one-factor scale is 0.987, and the perceived physical competence subscale of the Self-Perception Profiles for Children and TPPC have a Spearman correlation coefficient of 0.469 (95% confidence interval = 0.269–0.630). Discussion: Having a psychometrically strong scale to measure perceived physical competence of individuals with visual impairments is the first step in being able to replicate current, seminal research among this unique population. This adaptation of Harter’s perceived physical competence subscale uniquely assesses the child’s perceptions of physical competence among peers with visual impairments. This measure, coupled with the power to examine its predictive abilities, is important for children and adolescents with visual impairments, since they possess great tendencies for obesity and sedentary behavior. Implications for practitioners: If practitioners would like to change tendencies for obesity and sedentary behavior, then, they must include perceptions of physical competence as a latent construct. Now, practitioners can feel confident to do so for this highly vulnerable population.

Keywords

self-perception blindness disability physical activity motor development

In comparison with sighted peers, children and adolescents with visual impairments (i.e., those who are blind or have low vision) are at increased risk of becoming obese (Weil et al., 2002) and show lower levels of fitness, physical activity engagement, and actual motor competence (Augustad & Jiang, 2015; Houwen et al., 2009; Wagner et al., 2013). In addition to these differences in behaviors, children and adolescents with visual impairments also tend to report reduced perceptions of motor competence compared to peers without visual impairments (Brian et al., 2016, 2018). Individuals’ perceptions of their own motor competence have been shown to be strongly related to physical activity engagement (Babic et al., 2014; Brian et al., 2016), and those with reduced perceptions of motor competence may be at increased risk for sedentary lifestyle trajectories (Robinson et al., 2015; Stodden et al., 2008). Specifically, individuals with more positive perceptions of their own motor competence tend to engage in physical activities, choose activities that require more sophisticated motor skills, and persist in the face of challenges (Davison et al., 2006; Goodway & Rudisill, 1997). Interventions targeting the improvement of health and motor outcomes for children and adolescents with visual impairments should include elements aimed at boosting individuals’ perceptions of their own motor competence. But first, one must be able to confidently measure the perception of motor competence in children with visual impairments.

Despite their increased risk of negative health outcomes related to motor skills and perceptions of competence, little is known about how individuals with visual impairments perceive their own motor competence and how these perceptions may vary among peers with and without visual impairments. This dearth of information may partially be due to the lack of appropriate instruments that are available for use with this population. Most instruments that are used to measure perceived motor competence are not appropriate for use with individuals with visual impairments due to the delivery method requiring participants to select a picture that best illustrates their abilities, such as the Pictorial Scales for Perceived Competence and Social Acceptance (Harter & Pike, 1984) or because of a lack of validity and reliability estimates among populations with visual impairments.

The Perceived Physical Competence Subscale of the Self-Perception Profiles for Children (Harter, 1985) is often used for evaluating perceptions of physical competence of children and adolescents without disabilities (Babic et al., 2014). Results from the Perceived Physical Competence Subscale of the Self-Perception Profiles for Children show how children compare themselves to a peer “like them” in activities that purportedly combine to provide a measure of global self-worth regarding the physical domain. According to Harter’s own Competence Motivation Theory, (Harter, 1978) children manifest self-perceptions by comparing themselves to peers like themselves, can differentiate multiple domains of competence (e.g., physical vs. social) in middle childhood and beyond, and can be accurate when the questions pertain to activities that are familiar and relevant to them. However, no items contained the ability to differentiate between how children with visual impairments would feel in comparison to peers with visual impairments or without visual impairments. Moreover, the items may not be specifically targeted for children with visual impairments, a violation of Harter’s own theory mentioned above. These concerns warrant the creation of a new heuristic that is specifically targeted to meet the needs of children with visual impairments.

The first step in addressing this gap, the development of the Test of Perceived Motor Competence for young children with visual impairments, yielded a brief measure that produced data with strong estimates of face, content, and construct validity and reliability (Brian et al., 2017). However, this tool was developed for use among children aged 3–8 years and only focused on gross motor skills. Young children tend not to be cognitively capable of handling abstract constructs (e.g., those about physical activity) and need specific items for self-ratings (e.g., questions relating to how they dribble a ball). Adolescents, on the other hand, are cognitively capable of handling measures of global self-worth that transcend across the physical domain. Thus, an additional measure that is appropriate for adolescents aged 9–19 years was still needed that captured a more global measure of physical competence.

In this work, we aimed to extend previous efforts and created a tool, the Test of Perceived Physical Competence (TPPC) for students aged 9–19 years, which would be useful for capturing perceptions of physical competence among children and adolescents with visual impairments between the ages of 9 and 19 years. If psychometrically sound, the TPPC could help elucidate the relationship between perceptions of motor competence and physical activity engagement in children and adolescents with visual impairments. The purposes of this study were to examine the (a) face value and (b) divergent validity, (c) internal consistency, and (d) factor structure of the TPPC. Given the that Test of Perceived Motor Competence showed robust psychometrics (see Brian et al. (2017) for more information), we hypothesized that (a) a panel of experts would deem the TPPC strong regarding content and face validity, (b) that the TPPC would diverge from the Perceived Physical Competence Subscale of the Self-perception Profiles for Children as the TPPC was created specifically to remediate the problems with the Self-perception Profiles for Children, (c) that McDonald’s Omega values would be strong for internal consistency, and (d) that there would be six items that would load into one latent construct, perceived physical competence.

Methods

Instrument development

A panel of experts (N = 12) all participated to assist with the initial face and content validity for the TPPC. The panel included higher education professionals in developmental psychology (n = 1), adapted physical education (n = 2), and motor development (n = 3), as well as, practitioners in adapted physical education (n = 1), teachers of the visually impaired (n = 2), and adolescents with visual impairments (n = 3).

Prior to the creation of the TPPC, we first asked experts, via email, to comment on the relevance of Harter’s original Perceived Physical Competence Subscale of the Self-Perception Profiles for Children for children with visual impairments. The Perceived Physical Competence Subscale of the Self-Perception Profiles for Children contains either five (adolescent version) or six (child version) items. The items range from questions about sports (globally), new activities, how they compare to peers their age at sports, new outdoor games, and feelings about their own athleticism. The experts raised several issues immediately. First, experts were concerned that children with visual impairments would provide different answers for each item if they were comparing themselves to peers with visual impairments versus peers without visual impairments. For example, one item from the Perceived Physical Competence Subscale of the Self-Perception Profiles for Children (Harter, 1982) states, “Some kids wish they could be a lot better at sports; or, other kids feel they are good enough at sports” (see Table 1 for more subscale items). Multiple experts made comments to the effect of, “Are they playing with other kids with visual impairments or with kids without visual impairments? Answers would be greatly different.” A second issue was raised pertaining to the nature of the activity. For example, for the statement, “In games and sports some kids usually watch instead of play or other kids usually play instead of watch (Harter, 1982),” three experts asked if the activities being referenced were accessible activities like goalball, if the game was being played on an accessible device, if the student was familiar with the activity, if the student had been introduced to the activity (i.e., were they “pre-taught” it). Experts raised more questions and concerns with the Perceived Physical Competence Subscale of the Self-Perception Profiles for Children than supportive points. All experts agreed that a new tool was needed for students with visual impairments.

Table 1.

Perceived Physical Competence Scale from the Self-Perception Profiles for Children.


1. Some kids do very well at all kinds of sports	or, other kids don’t feel they are very good when it comes to sports
2. Some kids wish they could be a lot better at sports	or, other kids feel they are good enough at sports
3. Some kids think that they could do well at just about any new sports activities they haven’t tried before	or, other kids don’t feel they can play as well
4. Some kids feel that they are better than others their age at sports	or, other kids don’t feel they can play as well
5. In games and sports some kids usually watch instead of play	or, other kids usually play instead of watch
6. Some kids don’t do well at new outdoor games	or, other kids are good at new games right away

Note. Harter, 1985

Next, we created the TPPC, specifically aligned with Harter’s Motivation Theory (Harter, 1978) and in the same structure as the Perceived Physical Competence Subscale of the Self-Perception Profiles for Children, given its strong initial psychometrics (Harter, 1985). Afterward, we asked each expert, again via email, a series of three questions pertaining to each of the six items on the TPPC. First, were the items relevant to the lives of children and adolescents with visual impairments; second, were each of the items clearly written; and, third, were each of the items independent of each other? The experts were asked to rate each of the six items within the TPPC on a scale of 1 (not at all) to 5 (completely) for all three aspects (relevance, clarity, and independence). Finally, we asked each expert to provide any additional feedback for all six items or for the overall scale. The review process only required two iterations with the experts. After the first wave, no item scored below a four for any category. Comments were limited to small wording suggestions (e.g., provide an example or be more specific). We made all adjustments, sent back, via email, for further suggestions, and scores from round two increased from 4.12 to 4.55 out of 5.

Creation, application, and analysis of the Test of Perceived Physical Competence

The TPPC was created specifically for adolescents with visual impairments and was modeled after the Perceived Physical Competence Subscale of the Self-Perception Profiles for Children for children and adolescents (Harter, 1982). The TPPC was composed of six questions. Each item featured a structure alternative response format based on a specific motor skill scenario. The adolescent had to select “really true” or “sort of true” for one of the two questions comprising each item. “Really true” for the left question would denote a score of 1, signifying not at all physically competent, and “really true” on the right question would denote a score of 4, signifying very physically competent. The scoring was modeled after Harter’s Perceived Physical Competence Subscale of the Self-Perception Profiles for Children. Items one and four were worded in opposite order, and thus reverse scored for the analysis. For items five and six, which measure willingness to engage in sports and physical activities, the adolescent is told they can use assistive devices (i.e., long cane, dog guide, and the like) or a human guide or both. Prior to administration, the TPPC was vetted through a panel of experts.

Participants

All participants attended a week-long sports camp for children with visual impairments, including those who are deafblind, located in the New York state. Participants who were enrolled at the sports camp were eligible to be a part of this study. No participants who identified as deafblind chose to participate in this study. Approximately 89% of campers (179 out of 201) participated in the study. Participants who completed the TPPC (N = 179) included a range of ages from 9 to 19 years (M_age = 13.82 years; SD = 2.58), biological sex (boys = 98; girls = 81), self-reported degree of visual impairment (blind = 92; low vision = 87), race or ethnicity (Caucasian = 148; African-American = 25; and Asian = 6), and school type (public = 157, private = 8; special = 11; home = 3).

A subset of the total sample (n = 75, boys = 41, girls = 34; Caucasian = 56, African-American = 12, Asian = 6; blind = 27, and low vision = 48) also completed the Self-Perception Profiles for the Children Perceived Physical Competence Subscale. The subset also included ages that ranged from 9–19 years (M_age = 13.28 years; SD = 2.36) and school type (public = 64, private = 4; special = 6; home = 1). See Table 2 for further details.

Table 2.

Descriptive statistics for participants by test.

Test	N	Blind/Low Vision	Height (m)	Weight (kg)	BMI
SPPC
9–11 yearrs	28	12/16	1.47 (.11)	40.87 (11.33)	18.65 (3.25)
12–14 years	28	7/21	1.59 (.10)	59.31 (19.57)	23.02 (6.40)
15+	18	8/11	1.70 (.12)	64.61 (17.20)	22.07 (4.21)
Total	75	27/48	1.57 (.14)	53.62 (19.04)	21.14 (5.21)
TPPC
9–11 years	73	43/30	1.46 (.10)	40.90 (11.22)	18.76 (3.28)
12–14 years	76	35/41	1.61 (.10)	56.77 (16.20)	21.76 (5.36)
15+	30	14/16	1.65 (.12)	60.63 (15.72)	21.95 (4.03)
Total	179	92/87	1.58 (.13)	53.63 (16.77)	20.99 (4.63)

Note. BMI = Body mass index kg/m², height is in meters, weight is in kilograms, TPPC = Test of Perceived Physical Competence, and SPPC = Self-Perception Profiles for Children Perceived Physical Competence Subscale. Those who completed the SPPC are also captured within the demographics of the TPPC as those participants completed both tests.

Procedures

This study featured a cross-sectional, descriptive-analytic design with convenience sampling. All participants provided verbal assent and their parents or guardians provided written informed consent. The institutional review boards of all authors approved the procedures in this study. Participants completed both tests and a demographic questionnaire with a member of the research staff upon arriving at camp. Research staff members included the lead researcher, four doctoral students, and one undergraduate student. The four doctoral students were seeking degrees in adapted physical education and motor behavior. All four doctoral students had significant previous experience in physical education and sports camp settings for children and adolescents with visual impairments. The undergraduate student was a member of the honors college, pursuing a teaching license in physical education, and he had applied receive a masters in adapted physical education. The undergraduate student also had previous experience working with children and adolescents with visual impairments in physical education settings. The lead researcher trained all staff members, who passed protocol checks at 100% prior to implementation. Research staff members read participants the same script aloud to each participant; it included demographic questions and the items on each test. Overall, each interview required approximately 15–20 minutes. We only tested a subset of the main dataset on the Self-Perception Profiles for Children due to time constraints.

Data analysis

SPSS version 25 was used to conduct data screening, descriptive statistics analysis, reliability, and correlation for both the Perceived Physical Competence Subscale of the Self-Perception Profiles for Children and the TPPC.

As one of the main purposes of this study, the researchers aimed to confirm the structure of the TPPC that included six perceived physical competence items for children and adolescents with visual impairments. Exploratory Factor Analysis followed by Confirmatory Factor Analysis is one of the most common approaches to scale development and validation (Worthington & Whittaker, 2006), unless development and theory provide strong underpinnings to the number of factors present. In these situations, researchers can choose to run either an Exploratory Factor Analysis or Confirmatory Factor Analysis, but both are not needed (Kline, 2005). To confirm the hypothesized one-factor structure, Confirmatory Factor Analysis was used in Mplus version 8.5 with a robust weighted least squares approach mode of estimation since the items involved an ordinal, 4-point scale. Among the weighted least squares estimators, we used the weighted least squares mean estimator as it is better than weight least squares mean variance adjusted for sample sizes under 200 (Bandalos, 2014). Multiple fit statistics were utilized to confirm the factor structure, including Root Mean Square Error of Approximation, Comparative Fit Index, and Standardized Root Mean Square Residual. These fit indices measured the degree to which the factor model reproduced the empirical covariance matrix.

Results

Table 3 contains the means and SDs for the six items composing the TPPC.

Table 3.

Descriptive means and SD for Test of Perceived Physical Competence items.

Test of Perceived Physical Competence Item	Mean	SD
1. Some people believe they cannot/can play games or sports (like basketball, tag, or soccer) with their sighted peers	3.18	0.94
2. Some people believe they cannot/can play games or sports (like goal ball, beep baseball, or tag) with peers with visual impairments	2.98	1.06
3. Sometimes adults tell people with visual impairments that they are not capable of playing sports and games (like basketball, tag, or soccer). I am unwilling/willing to play games or sports when adults say I am not capable of doing so	3.00	1.03
4. Sometimes adults tell people with visual impairments that they are capable of playing sports and games (like basketball, tag, or soccer). I am unwilling/willing to play games or sports when adults say I am capable of doing so	3.13	0.94
5. Some people are unwilling/willing to be physically active in areas that they know very well and with which they are very familiar	3.03	1.03
6. Some people are unwilling/willing to be physically active even in areas that are brand new to them	2.90	1.05
Average of Items 1–6	3.32	0.70

To confirm the fit of the one-factor model, a Confirmatory Factor Analysis was run with the weighted least squares mean estimator to accommodate the ordinal nature of the items (Lai, 2018). The value of Root Mean Square Error of Approximation was 0.196 (90% confidence interval = 0.154–0.240), indicating poor approximation to the data (Hu & Bentler, 1999). However, for models with small degrees of freedom (df = 9) and smaller sample size (N= 179), the Root Mean Square Error of Approximation can exceed cutoffs very often, even when the model is correctly specified. For models such as the one we have here, researchers recommend not using the Root Mean Square Error of Approximation in determining model fit (Kenny et al., 2015; Kenny & McCoach, 2003). The Standardized Root Mean Square Residual result of 0.053 demonstrated an acceptable fit, as the Standardized Root Mean Square Residual should ideally be below 0.80 (Hu & Bentler, 1999). The Comparative Fit Index result of .95 also indicated acceptable fit as the Comparative Fit Index should ideally be at least .90 (Hu & Bentler, 1999).

Factor loading and error variance of each item of the TPPC (N = 179) are listed in Table 4. The percent of variation in each item explained by the factor varied from 44% (item 3) to 63% (item 6). McDonald’s Omega for the one-factor scale is .99, and the Perceived Physical Competence Subscale of the Self-Perception Profiles for Children and TPPC have a Spearman correlation coefficient of .47 (95% confidence interval = .27–.63).

Table 4.

Factor loadings from confirmatory factor analysis for Test of Perceived Physical Competence items.

Test item	Factor loading	Standard error
1. Some people believe they cannot/can play games or sports (like basketball, tag, or soccer) with their sighted peers	0.68	0.05
2. Some people believe they cannot/can play games or sports (like goal ball, beep baseball, or tag) with peers with visual impairments	0.75	0.04
3. Sometimes adults tell people with visual impairments that they are not capable of playing sports and games (like basketball, tag, or soccer). I am unwilling/willing to play games or sports when adults say I am not capable of doing so	0.66	0.05
4. Sometimes adults tell people with visual impairments that they are capable of playing sports and games (like basketball, tag, or soccer). I am unwilling/willing to play games or sports when adults say I am capable of doing so	0.67	0.05
5. Some people are unwilling/willing to be physically active in areas that they know very well and with which they are very familiar	0.72	0.04
6. Some people are unwilling/willing to be physically active even in areas that are brand new to them	0.79	0.04

Note. All factor loadings were significant, p-value < .01.

Discussion

The purpose of this study was to conduct a measurement analysis on the newly created TPPC, which included reliability testing and explored divergent validity with the Perceived Physical Competence Subscale of the Self-Perception Profiles for Children. This study was necessary because at present no existing measure captures perceptions of physical competence specifically among adolescents with visual impairments. Other scales either fail to be ecologically appropriate or lack validity and reliability or both for children and adolescents with visual impairments. This unique survey measures perceptions of competence with physical activities with peers both with visual impairments.

Preliminarily, our expert raters all conveyed positive comments regarding the relevance, clarity, and independence of each item. These findings were not surprising, since few edits were required, scores were high, and enthusiasm communicated. We were fortunate to have a diverse set of experts ranging from faculty in university settings to practitioners to individuals who experience visual impairments. As comments and enthusiasm were shared across the categories of raters, we felt confident to move forward to the next phase for the psychometric evaluation of the TPPC, construct validity.

According to the results, all six items were retained and loaded onto a single factor of perceptions of physical competence, as expected. All fit indices showed satisfactory fit with the one-factor model, except the Root Mean Square Error of Approximation. However, due to the minimal degrees of freedom and smaller sample, researchers suggest not using the Root Mean Square Error of Approximation as a fit statistic due to the large point estimate, as well as the large confidence interval (Kenny et al., 2015). In conclusion, the Confirmatory Factor Analysis confirmed that all six items represent a factor of perceived physical competence in adolescents with visual impairments.

Aside from factor structure, reliability and divergent validity were examined. Reliability results confirm the six-item scale was highly reliable. As for divergent validity, there was a moderate, positive correlation (r = .47) with Harter’s perceptions of physical competence subscale. We anticipated this finding and argue the divergent validity as the crux for creating the TPPC in the first place. We hypothesized that Harter’s scale and the TPPC would diverge. This hypothesis was retained. The Harter scale is not adaptable or ecologically valid for children and adolescents with visual impairments and consequently failed to capture perceptions of physical competence of participants with visual impairments.

Limitations

With the results of this study, researchers can utilize the TPPC with relative confidence among individuals with visual impairments aged 9–19 years; however, limitations exist. The measurement analyses were conducted on a sample size of 179, but generally at least 200 is preferred. Furthermore, since some adolescents in the sample did not have scores on Harter’s physical competence subscale, the divergent validity was calculated for only 75 children. Finally, we recognize that only including participants from a sport camp setting may limit the generalizability of our findings.

Future research

Future research should explore differences in the TPPC based upon degree of visual impairment, school type, sex, and race or ethnicity and include participants outside of sport camp contexts. These analyses should include differential item functioning to exclude bias in the answers on items from contextual factors. Furthermore, research can now begin to fill the gap with regard to physical activity and motor competence among children and adolescents with visual impairments. Perceived competence (Barnett et al., 2011; Hands et al., 2009) and motor competence are seen as indicators of participation in physical activities that promote positive health outcomes (Hands et al., 2009; Stodden et al., 2008). However, future research needs to explore this predictive relation in children and adolescents with visual impairments. Furthermore, does the predictive relationship vary for children and adolescents without visual impairments and those with visual impairments? Predictive relationships should not be misinterpreted as factors of causality. Once predictive relationships are better established, we can then conduct future randomized trials to explore mechanisms that “cause” physical activity behaviors. Until then, we must continue to explore factors that associate with physical activity behaviors that can serve as underlying mechanisms predicting positive developmental trajectories for health.

Implications for practitioners

Having a psychometrically strong scale to measure perceived physical competence in adolescents with visual impairments is the first step in being able to replicate current, seminal research among this unique population. This adaptation of Harter’s perceived physical competence subscale uniquely assesses the child’s perceptions of physical competence among peers with visual impairments. This measure coupled with the power to examine its predictive abilities is important for children and adolescents with visual impairments, as they possess great tendencies for obesity and sedentary behavior. If practitioners would like to change tendencies for obesity and sedentary behavior, then they must include perceptions of physical competence as a latent construct. Practitioners can now feel confident to do so for this highly vulnerable population.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Ali Brain

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