Devices that measure our physical, medical and mental condition have entered daily life recently. Such devices status in a continuous manner can be useful predicting future events or guide us towards healthier life. It is therefore important to establish such record behaviour reliable what we believe they measure. In this article, propose the reliability validity of newly developed measuring de...

Many longitudinal studies collect data that have irregular observation times, often requiring the application of linear mixed models with time-varying outcomes. This paper presents an alternative splits quantitative analysis into two steps. The first step converts irregularly observed a set repeated measures through broken stick model. second estimates parameters scientific interest from measur...