SSCI Overview

The Signals and Systems Concept Inventory (SSCI) is a 25 question multiple-choice exam designed to assess students' understanding of core concepts taught in undergraduate linear signals and systems courses, which are an integral part of electrical and computer engineering curricula. The SSCI emphasizes conceptual understanding over computational mechanics, and contains distractors, or incorrect answers, designed to capture common student misconceptions. There are separate versions for continuous time and discrete time topics. To date the SSCI has been tested on over 2250 students at 17 schools. In 2008 it was translated into Spanish and Chinese.

SSCI Development

The SSCI is one of several concept inventory exams whose initial development was funded by the National Science Foundation through the Foundation Coalition in response to a growing need for assessment tools for the undergraduate engineering curricula. One approach to measuring student learning is to administer a standardized conceptual exam as both a pre-test and a post-test and compute the gain during the semester. This technique can be used to assess the effectiveness of various pedagogical techniques as well as curriculum reform efforts. Our efforts in developing the SSCI were inspired by the Force Concept Inventory developed by Hestenes et al. to measure students' understanding of Newtonian physics.

2005-2010 Study

With funding from the National Science Foundation Assessment of Student Achievement program, we are continuing the development of the SSCI. The goals of the current study are as follows:

  • Collect SSCI performance, academic, demographic data
  • Verify construct and content validity and reliability
  • Compile gain statistics for S&S courses
  • Refine the CT and DT versions of the SSCI
  • Disseminate the exams and results of the study
To achieve these goals, we are working with a development team of S&S instructors at twelve schools: Duke, Embry-Riddle, George Mason, Marquette, Notre Dame, Rice, Rose Hulman, Santa Clara, UC Berkeley, UT-El Paso, UMass Dartmouth, and Wyoming. In addition to administering the SSCI at these schools, we are also conducting detailed interviews with S&S students at George Mason University and UMass Dartmouth.

New Versions Available

Version 5.0

As of Feburary 2010, version 5.0 of the SSCI exams are available. The exams were revised based on item response theory (IRT) analysis and feedback from the development team. For more information about IRT, see our January 2009 paper from the IEEE Signal Processing Education Workshop.

Spanish Version 4.0

Thanks to Luis Vicente of the Universidad de Zaragoza, the Spanish translation of version 4.0 of the SSCI exams is now available. We hope to make Spanish version 5.0 available in the near future.

Exam access

To obtain copies of the exams or more information about the SSCI study, email John Buck (johnbuck [at] or Kathleen Wage (k.e.wage [at]