USAGE.md

In sem-in-r/seminr: Building and Estimating Structural Equation Models

title: "Different Use Cases of Seminr Syntax" output: pdf_document

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

Measurement

Measurement mode: reflective vs. formative

You can specify formative or reflective constructs:

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

Structure

Notice there are multiple ways to specify the same structural 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")
)

sem-in-r/seminr documentation built on Aug. 26, 2022, 8:47 p.m.