For every researcher, the "Call for Papers" always ends with a promise: "Proceedings will be submitted for indexing in..."

Usually, you see two acronyms: EI (Compendex) and Scopus.

While both are owned by Elsevier and both are markers of quality, they are not identical.² In some academic circles, one is considered the "Gold Standard" while the other is just a "Nice to Have." Choosing the wrong one can mean your paper doesn't count toward your PhD requirement or grant application.

So, in the battle of EI vs. Scopus, which one wins? The answer depends entirely on your field of study.

1. What is EI Compendex? (The Engineer's Bible)

EI stands for Engineering Index.³ It is the oldest and most comprehensive bibliographic database dedicated specifically to the engineering field, dating back to 1884.⁴

• The Scope: It is Deep, Not Wide. It focuses exclusively on engineering and applied physical sciences (CS, EE, Civil, Mechanical, Chemical).

• The Reputation: For traditional engineering disciplines, EI is the historical benchmark. If you are a Civil or Mechanical Engineer, an EI-indexed paper is often the primary requirement for graduation.

• The Rigor: EI is historically perceived as being slightly stricter regarding the engineering relevance of the content.

2. What is Scopus? (The Modern Giant)

Scopus is a much younger database (launched in 2004), but it has grown to become the largest abstract and citation database in the world.

• The Scope: It is Wide, Not Deep. It covers everything: Science, Technology, Medicine, Social Sciences, and Arts & Humanities.

• The Reputation: Scopus is the engine behind modern university rankings (like QS and Times Higher Education).⁵ Because it tracks citations across all fields, it is essential for calculating metrics like your h-index.

• The Advantage: Because it is larger, Scopus papers often get more visibility outside of strict engineering circles.

The Head-to-Head Comparison

Which One Should You Choose?

There is no single "better" index. The value depends on your specific situation.

Scenario A: You are a Core Engineer (EE, CS, Civil, Mech)

Winner: EI Compendex (usually)

In many Asian and European universities, Engineering departments specifically mandate "EI retrieval" for PhD graduation. If you submit to a conference that is only Scopus indexed, it might not satisfy your departmental rules.

Scenario B: You are in Bio-Tech, Health, or Social Sciences

Winner: Scopus

EI Compendex likely won't even cover your field. Scopus is the standard here. Its broader reach ensures your work is connected to medical and social science literature.

Scenario C: You Care About Your h-index

Winner: Scopus

Scopus has the best tools for tracking citations. If your goal is to boost your h-index and track who is citing you, Scopus visibility is essential.

The "Double Indexing" Gold Standard

Here is the secret: You shouldn't have to choose.

The highest-quality conferences in the world—such as those sponsored by IEEE or ACM—are almost always indexed by BOTH EI Compendex and Scopus.

If a conference claims to be indexed by only one, ask yourself why.

• Is it an engineering conference that wasn't technical enough for EI?

• Is it a general conference that wasn't rigorous enough for Scopus?

The Verdict:

For maximum career safety and impact, always target conferences that guarantee Double Indexing (EI + Scopus). This ensures you satisfy the strict graduation requirements of engineering departments (EI) while building your citation metrics on the global stage (Scopus).