USAGE.md

In ISS-Analytics/modelr: Natural, friendly, domain-specific language for building PLS structural equation models

title: "Different Use Cases of Modelr Syntax" output: html_document

This document highlights the diffent types of modelr syntax for particular use cases in measurement and structural definitions.

Measurement

Measurement mode: reflective vs. formative

You can specify formative or reflective factors:

simple_mm <- measure(
  reflect("Expectation", multi_items("CUEX", 1:3)),
  form("Quality", multi_items("PERQ", 1:7))
)

Measurement items: multiple vs. single

You may specify multiple items or a single item to measure a construct. multi_items(...) specifies multiple items, and a single item can simply be named.

simple_mm <- measure(
  reflect("Quality", multi_items("PERQ", 1:7)),         # seven-item measure
  reflect("Satisfaction", multi_items("CUSA", c(1,3))), # two-item measure
  reflect("Expectation", "CUEX1")                       # single-item measure
)

Structure

Notice there are multiple ways to specify the same strucural model.

Structural style:

There are many ways to specify the same structure, depending on how you perceive the model. The following example shows three ways to specify the same structural model.

Output Structure Style:

mobi_sm <- structure(
  paths(from = "Image", to = c("Expectation", "Satisfaction", "Loyalty")),
  paths(from = "Expectation", to = c("Quality", "Value", "Satisfaction")),
  paths(from = "Quality", to = c("Value", "Satisfaction")),
  paths(from = "Value", to = c("Satisfaction")),
  paths(from = "Satisfaction", to = c("Complaints", "Loyalty")),
  paths(from = "Complaints", to = "Loyalty")
)

Regression Structure Style:

mobi_sm2 <- structure(
  paths(to = "Expectation", from = "Image"),
  paths(to = "Satisfaction", from = c("Image", "Expectation", "Quality", "Value")),
  paths(to = "Loyalty", from = c("Image", "Satisfaction", "Complaints")),
  paths(to = "Quality", from = "Image"),
  paths(to = "Value", from = c("Expectation", "Quality")),
  paths(to = "Complaints", from = "Satisfaction")
)

Mixed Structure Style:

mobi_sm3 <- structure(
  paths(from = "Image", to = "Expectation"),
  paths(from = "Expectation", to = "Quality"),
  paths(from = c("Expectation", "Quality"), to = c("Satisfaction", "Value")),
  paths(from = c("Image", "Value"), to = "Satisfaction"),
  paths(from = c("Image", "Satisfaction", "Complaints"), to = "Loyalty"),
  paths(from = "Satisfaction", to = "Complaints")
)

ISS-Analytics/modelr documentation built on May 7, 2019, 6:35 a.m.